The awkward bit at the top
This article has been published for the benefit of all model horse collectors. It is offered for free as my own investment into our wonderful hobby. I am always happy to discuss these subjects via email but this does take valuable time which, as a working Mum is a rare commodity these days! Previously I have developed a number of in-person workshops that were wonderfully fun and were welcomed by hobbyists looking to develop their skills. I pride myself on offering accurate information and quality illustrations. Sadly these in-person workshops have been postponed since Covid reared its ugly head, but I truly love teaching and do miss it terribly. Writing articles and creating informative content that educates and elightens is a passion I wish I could expand on, I would love to produce more articles covering all aspects of the subjects I can offer from my experiences.
If you have enjoyed this article and found is of value to you, and of course ONLY if you are in a comfortable position to do so, a small contribution would help me expand upon it. I don't drink coffee, so if you want to buy me a drink then the cost of a cup of tea would go a long way.
It is completely optional and you are most welcome to skip by this section, read on and enjoy this page and what it offers!
With your support I can enhance the page with illustrations and examples and make it even more useful to both new and seasoned collectors alike. If this goes well I will also be able to offer more articles that you may find useful during your involvement in our hobby.
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If you have enjoyed this article and found is of value to you, and of course ONLY if you are in a comfortable position to do so, a small contribution would help me expand upon it. I don't drink coffee, so if you want to buy me a drink then the cost of a cup of tea would go a long way.
It is completely optional and you are most welcome to skip by this section, read on and enjoy this page and what it offers!
With your support I can enhance the page with illustrations and examples and make it even more useful to both new and seasoned collectors alike. If this goes well I will also be able to offer more articles that you may find useful during your involvement in our hobby.
.
3D Printing - What you need to know:
3D printed models - they're taking over!! 2019 and 2020 saw a massive surge in 3D printed models being sold into the model horse hobby which is only set to continue to grow in 2021 and beyond, and you may feel a little overwhelmed by all the types and levels of quality out there. Here's a handy guide to help you navigate this new type of production. I've limited the information on this page to relevant printers and techniques; 3D printing is a very large subject, so the information below is currently the most relevant to our hobby in my opinion. All information is correct at the time of publication.
Quick guide - things to ask before buying a 3D printed model (all expanded on below):
What should I worry about when buying a 3D printed model? When buying any model horse we always have several things we look for. In plastic model we don't want to see seams, splits or scratches. On resins we don't want to see misalignment, exposed wires or bubbles, on china models we don't want to see flaws, cracks or crazing in the glaze. But what about 3d prints? Read on for a guide on what to look out for, what to worry about and what to love about 3D printed model horses!
Who sculpted this model? The first question is sometimes so obvious it doesn't get asked, but you always should! This is an important question, because a growing number of models being sold into the hobby now are actually re-creations of models by other artists. The first example of this was "Hawk" by Maggie Bennett, and also the skeleton model she produced for a while. This was all totally above board, transparent and acceptable, but I often see these models currently referred to as being sculpted by Maggie. In both cases, she DID do a tonne of work to make them suitable for production and rightly deserves the credit for her work, but the actual models were originally created by other people either by photogrammetry or digital sculpting. But recently more artists have printed and sold models that originated elsewhere (usually crediting the original artist, but not always), so be sure to do your homework and understand where the model originates from.
If taken from an existing clay sculpture (ie scanned and shrunk, minified etc), has the model been reworked to make it good for printing? This is certainly a buyer-beware question! Scanning models is as important as setting up the 3D print, it can be done well or it can be done badly. Either way, many models destined to be "minified" need a degree of re-working to enhance the details lost to scanning/shrinking and make for a better final result. Some don't - it depends on the sculptors style as to which subtle details may be lost, or become a bit... funny looking after the change in scale. Have you ever received a micro mini and you can't find the eye outlines? Or the ears may be so fine they break as soon as you touch them? These are examples of models that have not been correctly re-worked before production into mini form. As an example from my own experience, the Copperfox micro mini pewter models had months of work done to them to redesign them for micro mini production. I am proud that I can confidently say that on each one you can clearly see the eyes, the muscles are still defined and the ears are both clearly visible and strong enough to be painted and packed for shows etc, but it took a lot of work to get them to work properly for Micro Mini scale production. There are many ways to "scan-shrink-print" but doing it well takes a thorough understanding of the processes and risks involved (pewter casting has its own challenges too which have to be catered for, but that's talked about on another page).
Even digitally created models (ie sculpted from scratch on a computer, no clay involved) have challenges when being produced in different scales - a model that looks fabulous as a traditional scale 3D print might look bland and lose all definiteion as a micro mini, SM or Venti. On the other hand, 3D print a model designed to be a micro mini in a larger scale and you might laugh at what comes out! Simply scaling up or down and hitting print is not the best way to produce a model in several scales, but reworking the model at each scale takes more time and effort, so it's good to know if it's been done or not when investing in a model that's in a new scale. This is why it is always SO important to see an actual printed copy of the model before parting with your money, particularly with a new sculptor or a printing artist you've not bought from before, as printed models often turn out quite different to the rendered image you saw taken from the digital sculpture (but we all use those because they do make the model look awesome!), hopefully they are different in a good way, but you just don't know until you've seen it printed!
Who set up and printed the model? These days the original sculptor is rarely the person printing the copies for sale. Just as with traditional resin casting, there are good and bad examples. I would always refer to Rayvin here, as she is the epitome of GOOD 3D printing, she has done a tonne of research and experimentation to ensure her printed models are the best possible. I'd like to think my own models are also of such a high standard, but I'll let you be the judge of that. Sadly at the other end of the scale you have printing artists (ie the person setting up the print) who are more interested in making models fast and getting them sold en mass than in providing good quality. Unfortunately nobody would ever admit that, so it is up to you as a buyer to know who printed your model and which team they're on, wether they are being sold by the artist or another person.
What printer are they using? This is a perfectly valid question to ask your printing artist and they should answer you without hesitation. I won't claim that certain printers are better or worse, as so much of the process comes down to the skills of the person setting things up, but knowing who uses which printers will help you to understand which ones offer the qualities that you prefer.
What settings were used? This question may actually go unanswered if you ask it, as the specific settings printing artists use are often a rather closely guarded secret. It can take quite a lot of hard work finding out the best settings for your particular machine, and the time-investment isn't something that is easily given away freely. It's always worth an ask though, as certain settings are quite commonly used and knowing some of them is handy. The main setting is microns, this is the thickness of the layers used to print your model. Anything over 50 microns (or 50μm) should be avoided, however further details all depend on multiple factors (ie a 50 micron print from a Form 3 is very different to a 50 micron print from an Anycubic Photon).
I'm going to talk about DLP and SLA printers quite a bit from here on, there is more on these below so if it gets confusing scroll down and then come back to these questions.
Which resin or resin mixture is the model printed with? This is a MASSIVE question, especially with DLP printers. Standard DLP printing resin can be very brittle, it can warp, discolour and make for a very disappointing experience! However, with just a few drops of certain additives it can be strengthened and given that tiny bit of flexibility needed to make it robust enough for all we put our mode through. Again, a printing artist may be very reluctant to tell you their specific recipe as these have to be developed and take a lot of time investment, but they will probably be happy to share with you the base resin so you have an idea of what to expect. I won't list good and bad resins here as I've not used a DLP printer for a while and materials are developing so fast I wouldn't know which are currently best, sorry! SLA printers on the other hand have rather fewer resin options, also the resins are far more highly engineered and as a result cost much, much more (for me it's £150/$180 a litre vs £30/$36 a litre for a typical DLP resin). They have to use very specific settings and processes but generally result in better overall properties. I will caveat this and say that a well mixed recipe of DLP resins can certainly give a model just as strong as an SLA print, just watch that claims of super-strong prints you can thrown around without damage can actually also mean they're slightly bendy!
Who cleaned the model? Just as important as the sculptor and printing artist, is the person responsible for getting the model finished and beautifully smooth ready for you to prep and paint. 3D printed models don't have mould-seams like cast resins do (yey!) BUT they do have other challenges. The first one being the removal of all evidence of the support structures from the printing process and a constant challenge to do quickly enough to be able to continue selling (this is why I can't release as many new models as I'd like as I am both sculptor and printing/cleaning artist for the bulk of my models). This is a laborious process and hard to get super-clean - it is the main bottle-neck in my own production process and I'm constantly trying to find local help to expediate things! But done well you should receive a model that is practically ready to paint, which is awesome! Done badly (or worse, not at all!) and you'll be spending far more time on your model than you would on a resin or pewter cast.
For the sake of simplicity I'm going to focus on the most common types of printers being used in our model horse hobby, and the main model type we're seeing, which are generally micro mini in scale and produced in resin.
Quick guide - things to ask before buying a 3D printed model (all expanded on below):
- Who sculpted the horse? Sounds obvious, but is the seller the sculptor? Does the sculptor know their horses, anatomy, biomechanics and do they have the technical skills to apply this to the model in digital form (and did they sculpt from scratch, or start with someone else's model?!)
- If taken from an existing clay sculpture (ie scanned and shrunk, minified etc), has the model been reworked to make it good for printing? Simply scanning, shrinking and printing does not always make for the best quality result!
- Who set up and printed the model? Just like casting, printing quality depends heavily on the skills of the person doing it!
- What printer are they using? DLP or SLA, which brand, how old? These things matter and they're not overly complicated, read below.
- What settings were used? They may not divulge this but at least ask to see an actual print, not just a digital rendering of the model on offer.
- Which resin or resin mixture is the model printed with? So much variation!
- Who cleaned the model? who removed the supports and smoothed out any defects?
What should I worry about when buying a 3D printed model? When buying any model horse we always have several things we look for. In plastic model we don't want to see seams, splits or scratches. On resins we don't want to see misalignment, exposed wires or bubbles, on china models we don't want to see flaws, cracks or crazing in the glaze. But what about 3d prints? Read on for a guide on what to look out for, what to worry about and what to love about 3D printed model horses!
Who sculpted this model? The first question is sometimes so obvious it doesn't get asked, but you always should! This is an important question, because a growing number of models being sold into the hobby now are actually re-creations of models by other artists. The first example of this was "Hawk" by Maggie Bennett, and also the skeleton model she produced for a while. This was all totally above board, transparent and acceptable, but I often see these models currently referred to as being sculpted by Maggie. In both cases, she DID do a tonne of work to make them suitable for production and rightly deserves the credit for her work, but the actual models were originally created by other people either by photogrammetry or digital sculpting. But recently more artists have printed and sold models that originated elsewhere (usually crediting the original artist, but not always), so be sure to do your homework and understand where the model originates from.
If taken from an existing clay sculpture (ie scanned and shrunk, minified etc), has the model been reworked to make it good for printing? This is certainly a buyer-beware question! Scanning models is as important as setting up the 3D print, it can be done well or it can be done badly. Either way, many models destined to be "minified" need a degree of re-working to enhance the details lost to scanning/shrinking and make for a better final result. Some don't - it depends on the sculptors style as to which subtle details may be lost, or become a bit... funny looking after the change in scale. Have you ever received a micro mini and you can't find the eye outlines? Or the ears may be so fine they break as soon as you touch them? These are examples of models that have not been correctly re-worked before production into mini form. As an example from my own experience, the Copperfox micro mini pewter models had months of work done to them to redesign them for micro mini production. I am proud that I can confidently say that on each one you can clearly see the eyes, the muscles are still defined and the ears are both clearly visible and strong enough to be painted and packed for shows etc, but it took a lot of work to get them to work properly for Micro Mini scale production. There are many ways to "scan-shrink-print" but doing it well takes a thorough understanding of the processes and risks involved (pewter casting has its own challenges too which have to be catered for, but that's talked about on another page).
Even digitally created models (ie sculpted from scratch on a computer, no clay involved) have challenges when being produced in different scales - a model that looks fabulous as a traditional scale 3D print might look bland and lose all definiteion as a micro mini, SM or Venti. On the other hand, 3D print a model designed to be a micro mini in a larger scale and you might laugh at what comes out! Simply scaling up or down and hitting print is not the best way to produce a model in several scales, but reworking the model at each scale takes more time and effort, so it's good to know if it's been done or not when investing in a model that's in a new scale. This is why it is always SO important to see an actual printed copy of the model before parting with your money, particularly with a new sculptor or a printing artist you've not bought from before, as printed models often turn out quite different to the rendered image you saw taken from the digital sculpture (but we all use those because they do make the model look awesome!), hopefully they are different in a good way, but you just don't know until you've seen it printed!
Who set up and printed the model? These days the original sculptor is rarely the person printing the copies for sale. Just as with traditional resin casting, there are good and bad examples. I would always refer to Rayvin here, as she is the epitome of GOOD 3D printing, she has done a tonne of research and experimentation to ensure her printed models are the best possible. I'd like to think my own models are also of such a high standard, but I'll let you be the judge of that. Sadly at the other end of the scale you have printing artists (ie the person setting up the print) who are more interested in making models fast and getting them sold en mass than in providing good quality. Unfortunately nobody would ever admit that, so it is up to you as a buyer to know who printed your model and which team they're on, wether they are being sold by the artist or another person.
What printer are they using? This is a perfectly valid question to ask your printing artist and they should answer you without hesitation. I won't claim that certain printers are better or worse, as so much of the process comes down to the skills of the person setting things up, but knowing who uses which printers will help you to understand which ones offer the qualities that you prefer.
What settings were used? This question may actually go unanswered if you ask it, as the specific settings printing artists use are often a rather closely guarded secret. It can take quite a lot of hard work finding out the best settings for your particular machine, and the time-investment isn't something that is easily given away freely. It's always worth an ask though, as certain settings are quite commonly used and knowing some of them is handy. The main setting is microns, this is the thickness of the layers used to print your model. Anything over 50 microns (or 50μm) should be avoided, however further details all depend on multiple factors (ie a 50 micron print from a Form 3 is very different to a 50 micron print from an Anycubic Photon).
I'm going to talk about DLP and SLA printers quite a bit from here on, there is more on these below so if it gets confusing scroll down and then come back to these questions.
Which resin or resin mixture is the model printed with? This is a MASSIVE question, especially with DLP printers. Standard DLP printing resin can be very brittle, it can warp, discolour and make for a very disappointing experience! However, with just a few drops of certain additives it can be strengthened and given that tiny bit of flexibility needed to make it robust enough for all we put our mode through. Again, a printing artist may be very reluctant to tell you their specific recipe as these have to be developed and take a lot of time investment, but they will probably be happy to share with you the base resin so you have an idea of what to expect. I won't list good and bad resins here as I've not used a DLP printer for a while and materials are developing so fast I wouldn't know which are currently best, sorry! SLA printers on the other hand have rather fewer resin options, also the resins are far more highly engineered and as a result cost much, much more (for me it's £150/$180 a litre vs £30/$36 a litre for a typical DLP resin). They have to use very specific settings and processes but generally result in better overall properties. I will caveat this and say that a well mixed recipe of DLP resins can certainly give a model just as strong as an SLA print, just watch that claims of super-strong prints you can thrown around without damage can actually also mean they're slightly bendy!
Who cleaned the model? Just as important as the sculptor and printing artist, is the person responsible for getting the model finished and beautifully smooth ready for you to prep and paint. 3D printed models don't have mould-seams like cast resins do (yey!) BUT they do have other challenges. The first one being the removal of all evidence of the support structures from the printing process and a constant challenge to do quickly enough to be able to continue selling (this is why I can't release as many new models as I'd like as I am both sculptor and printing/cleaning artist for the bulk of my models). This is a laborious process and hard to get super-clean - it is the main bottle-neck in my own production process and I'm constantly trying to find local help to expediate things! But done well you should receive a model that is practically ready to paint, which is awesome! Done badly (or worse, not at all!) and you'll be spending far more time on your model than you would on a resin or pewter cast.
For the sake of simplicity I'm going to focus on the most common types of printers being used in our model horse hobby, and the main model type we're seeing, which are generally micro mini in scale and produced in resin.
So what actually IS 3D Printing?
You've heard the term banded about for a while now, you know it's different to resin casting or plastic injection moulding, but what does 3D printing actually mean?
3D printers build up a model by laying down very thin layers of resin on top of each other, building them up to make a fully 3D printed item. But before they do this, an artist must create the model in digital form - you cannot 3D print from a photo. This modelling is usually done in a computer program such as ZBrush, Blender or Nomad (there are LOTS of programs that can be used, I wouldn't say any are better than others, this part is all down to the skills of the sculptor) and starts either with a scanned digital version of a real (clay) model, or a virtual ball of clay which is sculpted in the same time consuming way as clay but inside a piece of software on a computer.
Then, once this difigal model is perfected, the person printing the model (who may not be the same person who sculpted it) sets it up to print, which involves rotating the model to the perfect orientation for good printing and adding a support structure; vertical pillars that print along with the horse to hold in in place and make sure that any overhanging parts print successfully. Printing artists (as I've now decided to call them) are the equivalent to casting artists, so for example, if I set up and print a model I am effectively now the Mountain View Studios of it, just using a printer and resin rather than a mould and resin to produce my copies.
Using more software (specific to the printer being used, so these vary), the model is then "sliced" by the software into layers to translate the 3D model into 2d data that the printer can understand. Each slice is effectively a black and white silhouette of the layer it represents. In theory you could create a 3d print from a regular ink printer, getting it to print out each slice on a piece of paper, you'd then have to cut them out and glue them together, but you'd end up with a 3d model created in a very similar way to the ones you see sold at the moment, albeit yours would be made of paper and glue, not resin.
Before slicing there are some important settings that control the quality of the final print. Just as with a regular printer, you have "Best" and "Draft" quality settings depending on whether you want quality or speed, the same goes with 3D printers. The main setting adjusts the thickness of each layer, so for a faster print you opt for thicker layers as there would be fewer, so it would print faster, but those layers will be quite visible, may obscure details and could be problematic for prepping, so generally a thinner layer is used to get a smoother finish. Be aware though - bizarrely, just cranking the printer up to maximum DOES NOT guarantee a perfect print! This is where an experienced and knowledgeable person needs to use their skills to get the settings just-so, for the best results.
After slicing, the print file (effectively a large number of black and white silhouette images) is sent to the printer which has been set up with a resin mixture specific to the requirements of that model, and off it goes. Generally a micro mini scale model can take anywhere between one hour and one day, depending on the printer and the number of models being printed at once.
After printing there are a few processing the model goes through, first it has to be washed, to remove all the uncured resin and give a nice crisp finish. Not done properly you will get shiny spots, sticky spots or even blurred areas where the details haven't been cleaned properly and liquid resin has filled in the details and later cured. Some printers then require a post-cure to strengthen the finished model, which just means the model is heated and exposed to strong UV light for a short amount of time. After that the printing process is complete and the model can be carefully removed from the supports that held it to the printer build plate, if not done carefully the supports can tear away, leaving little divots in the model which need to be filled (these are as annoying to prep as bubbles are in cast resins!). Once trimmed the model is "cleaned", this means sanded and filed to remove the little bumps left by the supports and sometimes a light sand is done in areas where print lines are visible.
Finished models can look a bit dusty from the final cleaning process mainly as they aren't usually white (which hides the dust and sanding marks on the white resin casts we are used to seeing), so the sanded areas show more, which is fine but they should not have any deep scratch marks showing from heavy-handed or rushed cleaning, and should not have visible support bumps. If they did this would class them as "raw" or "trimmed only" as they have had the supports trimmed away but have not been fully cleaned. Just as with cast resins, even well cleaned models may need a final once over after priming to remove all traces of their production.
3D printers build up a model by laying down very thin layers of resin on top of each other, building them up to make a fully 3D printed item. But before they do this, an artist must create the model in digital form - you cannot 3D print from a photo. This modelling is usually done in a computer program such as ZBrush, Blender or Nomad (there are LOTS of programs that can be used, I wouldn't say any are better than others, this part is all down to the skills of the sculptor) and starts either with a scanned digital version of a real (clay) model, or a virtual ball of clay which is sculpted in the same time consuming way as clay but inside a piece of software on a computer.
Then, once this difigal model is perfected, the person printing the model (who may not be the same person who sculpted it) sets it up to print, which involves rotating the model to the perfect orientation for good printing and adding a support structure; vertical pillars that print along with the horse to hold in in place and make sure that any overhanging parts print successfully. Printing artists (as I've now decided to call them) are the equivalent to casting artists, so for example, if I set up and print a model I am effectively now the Mountain View Studios of it, just using a printer and resin rather than a mould and resin to produce my copies.
Using more software (specific to the printer being used, so these vary), the model is then "sliced" by the software into layers to translate the 3D model into 2d data that the printer can understand. Each slice is effectively a black and white silhouette of the layer it represents. In theory you could create a 3d print from a regular ink printer, getting it to print out each slice on a piece of paper, you'd then have to cut them out and glue them together, but you'd end up with a 3d model created in a very similar way to the ones you see sold at the moment, albeit yours would be made of paper and glue, not resin.
Before slicing there are some important settings that control the quality of the final print. Just as with a regular printer, you have "Best" and "Draft" quality settings depending on whether you want quality or speed, the same goes with 3D printers. The main setting adjusts the thickness of each layer, so for a faster print you opt for thicker layers as there would be fewer, so it would print faster, but those layers will be quite visible, may obscure details and could be problematic for prepping, so generally a thinner layer is used to get a smoother finish. Be aware though - bizarrely, just cranking the printer up to maximum DOES NOT guarantee a perfect print! This is where an experienced and knowledgeable person needs to use their skills to get the settings just-so, for the best results.
After slicing, the print file (effectively a large number of black and white silhouette images) is sent to the printer which has been set up with a resin mixture specific to the requirements of that model, and off it goes. Generally a micro mini scale model can take anywhere between one hour and one day, depending on the printer and the number of models being printed at once.
After printing there are a few processing the model goes through, first it has to be washed, to remove all the uncured resin and give a nice crisp finish. Not done properly you will get shiny spots, sticky spots or even blurred areas where the details haven't been cleaned properly and liquid resin has filled in the details and later cured. Some printers then require a post-cure to strengthen the finished model, which just means the model is heated and exposed to strong UV light for a short amount of time. After that the printing process is complete and the model can be carefully removed from the supports that held it to the printer build plate, if not done carefully the supports can tear away, leaving little divots in the model which need to be filled (these are as annoying to prep as bubbles are in cast resins!). Once trimmed the model is "cleaned", this means sanded and filed to remove the little bumps left by the supports and sometimes a light sand is done in areas where print lines are visible.
Finished models can look a bit dusty from the final cleaning process mainly as they aren't usually white (which hides the dust and sanding marks on the white resin casts we are used to seeing), so the sanded areas show more, which is fine but they should not have any deep scratch marks showing from heavy-handed or rushed cleaning, and should not have visible support bumps. If they did this would class them as "raw" or "trimmed only" as they have had the supports trimmed away but have not been fully cleaned. Just as with cast resins, even well cleaned models may need a final once over after priming to remove all traces of their production.
DLP vs. SLA
So now you have an idea of the process, but what about all these different printers and different resins etc? It is a bit of a minefield, but I can simplify it a little here:
Firstly, there are many types of 3D printers, but I can split the main ones used in our hobby into two main types used for the models coming into the hobby; DLP and SLA.
(I'm conveniently skipping Hartland's FDM printed models for this article for the moment until I can expand on it, they use a totally different type of printing for their lovely irridescent prints)
DLP printers have a screen that sits directly under a flat tank (vat) of liquid resin. The bottom of the tank is clear to allow light through from the screen, this clear membrane is called a FEP sheet and it is slightly flexible. A flat build plate is lowered into the resin down to the bottom of the tank, with just a fraction of a millimeter between it and the FEP. The screen lights up the first slice/layer of the print, it shines ultraviolet (UV) light up through the FEP and onto the thin layer of resin between the FEP and the build plate, curing (hardening) it which also sticks it to both the FEP and the build plate. The build plate then lifts up, peeling the printed layer away from the FEP sheet. The printed later is stuck solid to the build plate, which is important as it will need to stay there while every following layer is printed and peeled away - which involves some strong forces! During printing with DLP printers, you can hear the FEP sheet as it stretched and snaps back against the screen with a "pop"!
Common examples of DLP machine brands include Anycubic, Phrozen, EPAX, Elegoo, Wanhao and Creality
The biggest benefits of DLP printers are the price, they have become more and more affordable and are getting better and better in quality. The earlier versions of these printers (going back just to just 2017!) used 2K screens. This refers to the number of pixels the screen has. If you think about your TV and how we've gone from standard definition up to HD, then UHD (4K) and now even 8K, the same thing is happening with printers. 4K printers are now common, which means they have twice the number of pixels to the original 2K printers. Just as with your TV, more pixels means a clearer image. In 3D printing terms, when there are a lower number of pixels available, the printed model can get what can look like little rings showing on the sides of the model, usually with horses these manifest most on the belly as is has the most subtle round-ness and is a larger flatter area then on the finer details. These rings are called "voxel marks" or "voxel rings". 4K printers will have reduced voxel rings vs. 2K printers as they have a higher resolution. Voxel marks are usually minimal and normally will disappear under primer, but be aware of this as they may require a little sanding, especially if from a 2K printer.
Click on the image below to see an example of a (primed) model printed on an older 2K machine, exhibiting an extreme display of voxel rings - these are not layer lines but marks left by the pixels on the screen. For illustrative purposes only - newer 3D printers are WAY better than this now!
I would love to add a photo of a model printed on a 4K printer if possible, to show the difference - contact me if you have any I could use here!
Firstly, there are many types of 3D printers, but I can split the main ones used in our hobby into two main types used for the models coming into the hobby; DLP and SLA.
(I'm conveniently skipping Hartland's FDM printed models for this article for the moment until I can expand on it, they use a totally different type of printing for their lovely irridescent prints)
DLP printers have a screen that sits directly under a flat tank (vat) of liquid resin. The bottom of the tank is clear to allow light through from the screen, this clear membrane is called a FEP sheet and it is slightly flexible. A flat build plate is lowered into the resin down to the bottom of the tank, with just a fraction of a millimeter between it and the FEP. The screen lights up the first slice/layer of the print, it shines ultraviolet (UV) light up through the FEP and onto the thin layer of resin between the FEP and the build plate, curing (hardening) it which also sticks it to both the FEP and the build plate. The build plate then lifts up, peeling the printed layer away from the FEP sheet. The printed later is stuck solid to the build plate, which is important as it will need to stay there while every following layer is printed and peeled away - which involves some strong forces! During printing with DLP printers, you can hear the FEP sheet as it stretched and snaps back against the screen with a "pop"!
Common examples of DLP machine brands include Anycubic, Phrozen, EPAX, Elegoo, Wanhao and Creality
The biggest benefits of DLP printers are the price, they have become more and more affordable and are getting better and better in quality. The earlier versions of these printers (going back just to just 2017!) used 2K screens. This refers to the number of pixels the screen has. If you think about your TV and how we've gone from standard definition up to HD, then UHD (4K) and now even 8K, the same thing is happening with printers. 4K printers are now common, which means they have twice the number of pixels to the original 2K printers. Just as with your TV, more pixels means a clearer image. In 3D printing terms, when there are a lower number of pixels available, the printed model can get what can look like little rings showing on the sides of the model, usually with horses these manifest most on the belly as is has the most subtle round-ness and is a larger flatter area then on the finer details. These rings are called "voxel marks" or "voxel rings". 4K printers will have reduced voxel rings vs. 2K printers as they have a higher resolution. Voxel marks are usually minimal and normally will disappear under primer, but be aware of this as they may require a little sanding, especially if from a 2K printer.
Click on the image below to see an example of a (primed) model printed on an older 2K machine, exhibiting an extreme display of voxel rings - these are not layer lines but marks left by the pixels on the screen. For illustrative purposes only - newer 3D printers are WAY better than this now!
I would love to add a photo of a model printed on a 4K printer if possible, to show the difference - contact me if you have any I could use here!
SLA printers are know as being "the expensive ones" and easily cost 10x the amount basic DLP printers can. Whereas DLP printers are aimed towards hobby markets, SLA printers are heavily engineered and are usually sold into more professional and even industrial areas. SLA printers use similar principles to DLP, but with a few important differences.
Common examples of SLA machine brands include Formlabs, B9 and Moai
In a similar way to DLP printers, SLA printers also have a build plate that lowers into a tank (vat) of resin with a transparent bottom. These printers, however, don't have a screen, they have a laser instead. The laser "draws" out the sliced image using strong UV light onto the bottom of the resin vat and fills it in using a hatching method (like colouring in with a pencil). This means that laser prints can take longer than DLP prints, certainly when multiple models are concerned, but as the laser moves in a vector motion (ie smoothly, so no pixels), there are no voxel marks. SLA printers still use layers to build up the model, the silhouette is drawn between the build plate, peeled away from the tank bottom and repeated, however, modern SLA machines use a "gentle peel" motion, where the resin tank is gently tilted so the printed layer peels slowly and without the suction forces that make DLP prints "pop" away from the tank bottom. The combination of the laser and this "low force peeling" reduces the layer lines we associate with 3D prints to almost invisible levels (providing you get the settings right!), though with ANY 3d printed item, you'll be able to find them if you look closely enough.
Click on the image below for a typical SLA printed model - you won't see voxel rings, you can see layer lines if you look closely enough, but primer alone would smooth any remaining visible lines away.
Common examples of SLA machine brands include Formlabs, B9 and Moai
In a similar way to DLP printers, SLA printers also have a build plate that lowers into a tank (vat) of resin with a transparent bottom. These printers, however, don't have a screen, they have a laser instead. The laser "draws" out the sliced image using strong UV light onto the bottom of the resin vat and fills it in using a hatching method (like colouring in with a pencil). This means that laser prints can take longer than DLP prints, certainly when multiple models are concerned, but as the laser moves in a vector motion (ie smoothly, so no pixels), there are no voxel marks. SLA printers still use layers to build up the model, the silhouette is drawn between the build plate, peeled away from the tank bottom and repeated, however, modern SLA machines use a "gentle peel" motion, where the resin tank is gently tilted so the printed layer peels slowly and without the suction forces that make DLP prints "pop" away from the tank bottom. The combination of the laser and this "low force peeling" reduces the layer lines we associate with 3D prints to almost invisible levels (providing you get the settings right!), though with ANY 3d printed item, you'll be able to find them if you look closely enough.
Click on the image below for a typical SLA printed model - you won't see voxel rings, you can see layer lines if you look closely enough, but primer alone would smooth any remaining visible lines away.
Click on the photo below to see two prints: one was printed on a DLP printer, one on an SLA - the quality is very similar! I should point out that both of these models are lovely and smooth, I used very strong lighting and a macro lens to highlight the layer lines/rings. With the right settings, superb results can be achieved from almost any printer. With the right resin mixture these models could also have similar properties in terms of tensile and flexural strength.
You can read more about DLP v SLA prints here: https://formlabs.com/uk/blog/resin-3d-printer-comparison-sla-vs-dlp
Here are a few pros and cons compared between DLP and SLA printers:
Here are a few pros and cons compared between DLP and SLA printers:
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DLP - Pros and Cons
Pros: Lower purchase price Lower consumables price Speed, especially on prints with multiples A wonderful array of colour and effect possibilities Small batch colours, easy swapover between resins Cons: Older machines can produce heavy voxel marks Layer lines can be quite visible Takes a lot of experimentation to find the best resin recipes If poor resin recipe used, models can be weak |
SLA - Pros and Cons
Pros: Smoothest surfaces currently possible No voxel marks Materials have best qualities "out of the bottle" Materials are consistent Cons: Costs are very high, not realistically accessible for hobbyists Often slower, especially for prints with mutiple models Limited colours and effects (no pearls or glow in the dark, boo!) Small batch resin use is restrictive, limiting the fun factor and ability to experiment. |
The main reason 3D printed models have finally exploded into our hobby is that the layer lines have now been reduces to a point (when set up right!) where a thin coat of primer will lead to a nice smooth finish, which at the end of the day is what we all want! Some (but not all!) printers have finally reached this important milestone, provided the sculptor and printing person both did their jobs right, of course!
So what happens when the person setting up the print DOESN'T get it right? Below you can see three models printed at different settings, they're just trimmed so ignore the support bumps. It's quite obvious to tell which was at the lowest (worst) settings! Which one would you say is printed at the highest settings? The model printed at the highest settings is actually the one to the right, but notice the strange shine it has, with what looks like grid lines on it. Cranking the settings up to the highest level is NOT always the answer to getting the best results. To be fair the highest settings will provide a good print, but the finish of the model (in this case) is not desirable and often looks rather untidy after the model is cleaned, not to mention the fact that this setting costs a great deal more in terms of consumable costs, so the most-often used settings for this printer and this scale of model is the more balanced settings used in on the middle model.
Click on the image to see it larger.
So what happens when the person setting up the print DOESN'T get it right? Below you can see three models printed at different settings, they're just trimmed so ignore the support bumps. It's quite obvious to tell which was at the lowest (worst) settings! Which one would you say is printed at the highest settings? The model printed at the highest settings is actually the one to the right, but notice the strange shine it has, with what looks like grid lines on it. Cranking the settings up to the highest level is NOT always the answer to getting the best results. To be fair the highest settings will provide a good print, but the finish of the model (in this case) is not desirable and often looks rather untidy after the model is cleaned, not to mention the fact that this setting costs a great deal more in terms of consumable costs, so the most-often used settings for this printer and this scale of model is the more balanced settings used in on the middle model.
Click on the image to see it larger.
So that is 3D printing in the hobby as it currently stands, in a nut-shell.
The difference between models at each end of the quality scale with 3D printing can be astonishing! So always refer back to the list at the top of this page when inquiring about a 3D printed model you want to buy. You don't always need to aim for models at the very top end though - there are benefits to models throughout the scale just as there are with plastic, resin and china models. As long as you make an informed choice and know what to expect from your chosen artist/printer, you can look forward to receiving a model you can appreciate for all its best qualities!
The difference between models at each end of the quality scale with 3D printing can be astonishing! So always refer back to the list at the top of this page when inquiring about a 3D printed model you want to buy. You don't always need to aim for models at the very top end though - there are benefits to models throughout the scale just as there are with plastic, resin and china models. As long as you make an informed choice and know what to expect from your chosen artist/printer, you can look forward to receiving a model you can appreciate for all its best qualities!
I bought a 3D printed model, how do I look after it?
Yey! You have a new model from your favourite artist, and it is 3D printed!
"But what's all this I've heard about keeping them in the dark? Should I be worried?"
3D printed models are just as tough as cast resin models but have a few differences you need to know. You won't find wires reinforceing 3D prints, because it's not actually possible to insert a wire during printing. Provided it is a suitable SLA resin or a good DLP "recipe" and printed at the correct settings, it is stiffer than cast resin so you won't get any sagging later down the line. On larger 3D prints, these are printed hollow, some warping can occur during curing so a horse with four feet down may wobble a little if it is larger and hollow, which is nothing to worry about so long as it has been completely washed and dried inside and you protect it from further UV exposure.
The sun: 3D printing resin is all about UV exposure. During printing intense UV light solidifies the resin. Afterwards, during post-curing it also stregthens it. After that the process is complete, however further exposure to UV light would continue to harden the resin and if too much UV exposure occurs, the model would become so hard it gets brittle and could even crack! Normal sunlight inside a house is much lower than the intense light used during printing, but it is still a low dose, and day by day it can affect the model and the resin may continue to cure beyond the perfect point, and ultimately it could become brittle. In bright direct sunlight this could happen in just a few days, but a model kept in a very shaded area could be displayed for weeks without over-curing.
To avoid damage from sunlight there are a few things you can do. Display your model in a very shady spot in your display case. Coat your display case glass with a UV protective film (this is a great thing to do regardless as it also protects against fading of paintwork or yellowing of cast resins, I highly recommend this!). You can keep the 3D printed model packed away until ready to paint (such a shame to do this though), or you could simply paint it! The sealers used during painting, and even the paint itself protects the resin against UV light, therefore halting the curing process and protecting your model into the future, and if you prefer to keep your model unpainted, then a few light coats of a UV protecting sealer spray will also do a great job protecting it!
"But what's all this I've heard about keeping them in the dark? Should I be worried?"
3D printed models are just as tough as cast resin models but have a few differences you need to know. You won't find wires reinforceing 3D prints, because it's not actually possible to insert a wire during printing. Provided it is a suitable SLA resin or a good DLP "recipe" and printed at the correct settings, it is stiffer than cast resin so you won't get any sagging later down the line. On larger 3D prints, these are printed hollow, some warping can occur during curing so a horse with four feet down may wobble a little if it is larger and hollow, which is nothing to worry about so long as it has been completely washed and dried inside and you protect it from further UV exposure.
The sun: 3D printing resin is all about UV exposure. During printing intense UV light solidifies the resin. Afterwards, during post-curing it also stregthens it. After that the process is complete, however further exposure to UV light would continue to harden the resin and if too much UV exposure occurs, the model would become so hard it gets brittle and could even crack! Normal sunlight inside a house is much lower than the intense light used during printing, but it is still a low dose, and day by day it can affect the model and the resin may continue to cure beyond the perfect point, and ultimately it could become brittle. In bright direct sunlight this could happen in just a few days, but a model kept in a very shaded area could be displayed for weeks without over-curing.
To avoid damage from sunlight there are a few things you can do. Display your model in a very shady spot in your display case. Coat your display case glass with a UV protective film (this is a great thing to do regardless as it also protects against fading of paintwork or yellowing of cast resins, I highly recommend this!). You can keep the 3D printed model packed away until ready to paint (such a shame to do this though), or you could simply paint it! The sealers used during painting, and even the paint itself protects the resin against UV light, therefore halting the curing process and protecting your model into the future, and if you prefer to keep your model unpainted, then a few light coats of a UV protecting sealer spray will also do a great job protecting it!
I hope you have found this article useful, I do plan to expand it when I can with illustrations and more information as it becomes available. If you would like to support this research please scroll to the top of this page.
Disclaimer. All information in this article is produced by me and is based on my own experience and research. Any errors are unintentional and will be happily rectified once highlighted to me. Contact me if you see anything here that is incorrect or you feel I should change.