A Basic Guide to Production Methods Used

within the Model Horse hobby

This article was written in March 2024 as a free, basic guide to the methods used to produce the most commonly collected models within the Model Horse hobby.  This guide is not all-encompassing and has been kept bite-size, the information presented in this article is true and complete to the best of our knowledge.  We disclaim any liability in connection with the use of this information.  This article is written in Standard British English.

Model horses are very generally grouped into three categories:

• Plastic
• Resin
• China

There are actually more materials and subdivisions within those, which can lead to some confusion and uncertainty, especially for those new to this lovely hobby.  I'd like to try to clarify some of this for you here and hope you find the information below helpful in making informed choices for your own collection.

Plastic

The term "Plastic", when used within the model horse hobby most often refers to models such as Breyer and Peter Stone.  These are injection moulded models where hot, liquid, melted plastic is injected into a metal mould, then cooled rapidly and ejected from the mould.  These plastic models are normally produced in two halves (from two moulds) and the pieces are then fused together to create a hollow model.

Other models that fall within this category are the likes of Schleich and Papo, made from a more rubbery type of plastic. These are also injection moulded, but as they are smaller they are injection moulded in a single, solid piece from one mould.

Most plastic models are painted in the factories using airbrushes with hand-painted details such as the eyes.

Plastic models are generally grouped into five size, or scales, these are:

• 1:9 Traditional
• 1:12 Classic
• 1:18 Little Bit
• 1:32 Stablemate
• 1:64 Micro Mini (Breyer Brand "Mini Whinnie")

"Custom Plastic" is a hobby term used for models that began life as factory-produced models, but that have been modified in some way by hobbyists/artists.  This could simply be some extra white markings added, or an etched design (where a sharp knife is used to scrape the original paintwork away in certain areas, to show the white plastic beneath), or something more drastic such as being cut into pieces and reassembled into a new pose with completely new paintwork added.  The latter are often referred to as "Drastic Customs".

Resin

The term "Resin" is usually used in the hobby to refer to artist-made resin models.  Specifically, they are classed as "Artist Resin" models as they are made/sold by individual artists, though there is also a smaller division referred to as "Commercial Resin" for resin models made in factories and sold in shops/stores.  I will focus on Artist Resins for this article:

Artist Resin models follow similar sizing standards to plastics, with Traditional and Classic scale being the same.  Stablemate scale is also referred to, however historically, as artists discovered that slightly larger than Stablemate scale was more popular, the term "Mini" is now used more often to cover models around this size.  More recently, the scale "Venti" (1:20) was established to give artists a definite scale factor to work to and, as it is a very popular scale amongst collectors, to help unify collections, so that a Venti model by one artist is in perfect scale to a Venti by another artist, unlike "Minis" which can vary quite a bit).  You may see other scale names referred to but these are the most common ones.

The most common type of resin used for Artist Resins is the white, polyurethane, cast resin, where the two-part liquid resin is mixed together and then poured into a silicone mould where a chemical reaction occurs, solidifying the resin to make the model.  These often have wire reinforcements in the legs and tails (or any part that is at risk of breakage) and can be either solid, where the resin is poured into a mould and left to cure - this is generally the chosen method for smaller resin models, up to 1:12 classic scale, or hollow, where a smaller amount of resin is poured into a mould, then the mould is sealed and placed into a roto-caster (a bit like a giant gyroscope) and rotated slowly, coating the inside of the mould fully as the resin cures, resulting in a hollow model.  Larger models are usually hollow, as it keeps the material costs down but more importantly, results in a lighter model which is better for shipping and much easier to work with for the artist that paints it.

Polyurethane resin comes in lots of different grades.  The chosen range preferred within the model horse hobby is the Smooth-Cast 300 range; this is a bright white resin and has proven to be the best choice for model horses.  There are also polyurethane resins that are clear, and white or clear can both be coloured using various pigments.

Historically, polyester resin was used for model horses.  This is often a darker, grey colour, it is very strong and hard, but also quite brittle, so can be difficult to work with and these models are more fragile than the slightly softer, more forgiving polyurethane resin.

Other models that fall into this category include pewter, and recently, 3D Printed models.

Pewter is a white metal alloy composed mostly of tin, with a small amount of copper, antimony, bismuth and sometimes lead.  In England pewter is always lead and nickel-free but globally it can vary. Pewter is melted into liquid form and then poured into the centre of a flat, fast-spinning rubber mould where it cools and solidifies quickly.  Pewter is a very cost effective method of producing higher numbers of models and is commonly used for the smaller models, such as the 1:64 scale Micro Minis.

3D Printed

Currently, 3D printed resin model horses are often classified within the hobby as Artist Resins, but I've separated 3D printing out as this production method is very different to resin casting, and it is a large subject that needs more clarification.

The term "3d Printing" is used for any model produced with additive manufacturing methods - this simply means that a machine "printed" layers of a certain material to build up a three dimensional model.

SLICING.  All of these 3D printing methods involve first taking a digital 3D file and splitting it into thin slices.  Each of these slices can then be exported as a flat image which becomes one layer of the final 3D printed model.  The software used to do this is referred to as "Slicing" or "Slicer" software.  Slicing software is also used to add support material around the model if needed, to prevent failures from overhanging or unsupported parts.

There are many types of 3D printer out there, with several varying types within our hobby.  I won't cover the global usage of 3D printing here, other than to say that currently plastic, resin, ceramics, bio-materials, metals and more are all being 3D printed, it is a HUGE subject, but within our hobby, we can split things down more simply.

There are three main types of 3D printer used in our hobby, which I shall expand on below:

• FDM
• DLP/LED
• SLA

FDM Printing

Image by Freepik

Most FDM printers are generally considered to be hobby machines, as they are affordable and simple to use, however FDM 3D printers are used a great deal in industry for prototyping and custom goods as you can print a one-off item without having to make any moulds.  FDM stands for "Fused Deposition Modelling" which simply means the material is melted, deposited and cooled, and it fuses to the previous layer.  These machines are usually recognisable by the round spools of filament that hang above or alongside the printer.  A filament (or thread) of plastic* is fed into a print-head, which melts the plastic and draws out a line of material onto a flat platform, much like a regular printer.  One layer is printed out, then the print-head rises a very small amount, and it draws out another layer on top of the first, and so on.  These layers fuse together as the melted plastic is laid over the previous layer, and a three dimensional model is built up.  FDM printers are relatively clean to run as there are no liquids involved, so they are a favourite amongst educational facilities and hobbyists.

* I use the term "plastic" loosely here; FDM printers can use a range of materials, including ABS plastic, Nylon, foam and PLA, which is a bioplastic so is considered more environmentally friendly and less toxic than other plastics, however it does not decompose well naturally (so incineration or industrial decomposition is needed).

Scopigno R., Cignoni P., Pietroni N., Callieri M., Dellepiane M. (2017). "Digital Fabrication Techniques for Cultural Heritage: A Survey". Computer Graphics Forum 36 (1): 6–21. DOI:10.1111/cgf.12781

FDM printed models are usually quite recognisable as you can easily see the layers on the surface of the printed item.  This isn't always a bad thing, as this gives the surface an iridescent sheen which is quite pleasant.  Also the filaments come in an array of colours and shimmering mixes, so for decorative items such as pots, vases and novelties they are a great option.

A pretty FDM 3D printed Trilobite. Photo by David Clode on Unsplash

FDM printers are evolving, and many of these printers are now capable of using two or more spools of filament in each print, opening up a larger range of colour combinations and material mixes.  They can't compete with the resin 3D printers when it comes to surface finish, but they have huge potential for general manufacture and should not be disregarded.

DLP/LED Printing

DLP/LED printers use a very different method to FDM printers, using liquid resin which is quite toxic in its uncured form, they are a more serious hobby machine and are used more in industrial settings and high-end manufacture.  DLP stands for Digital Light Processing, and LED for Light Emitting Diode.  Whilst DLP printers use a projector and LED* printers use an LED array to project the image they both essentially work in the same way, so are generally bundled together.

* (the image is projected by the LED through an LCD screen, so sometimes these printers are referred to as LCD printers, but in this subject they mean the same thing)

DLP/LED printers work by projecting light in the shape of each layer for a few seconds, onto the clear underside of a shallow tank of liquid resin.  Working up-side-down, a build plate is lowered into the resin until is sits just above the base of the tank.  The layer image is projected onto the underside of the tank which is made of a strong, flexible film (usually called the FEP

Scopigno R., Cignoni P., Pietroni N., Callieri M., Dellepiane M. (2017). "Digital Fabrication Techniques for Cultural Heritage: A Survey". Computer Graphics Forum 36 (1): 6–21. DOI:10.1111/cgf.12781