Casting is the process of creating metal objects by pouring liquid metal into a mould. In the context of tabletop games, nearly every miniature you'll use was cast. In ye olde days of wargaming, models were usually cast in lead alloys for their malleability and relatively low melting point. Changing views on the safety of such materials has seen manufacturers move to lead-free alloys since the 1980s, most metal models nowadays being made of tin, aluminum, or silver if you're feeling
classy pretentious and expensive.
This is an example process for metal or resin casting:
- The sculptor creates the master model. It may be called a "green" if it was sculpted in Green Stuff.
- Once the master is fully cured, he places the model in a box and fills the box with a different, molten material.
- Once that material is fully cured, the sculptor carefully splits the case in half, freeing the master sculpt from the brand-new mould.
- The sculptor cuts channels into the faces of the mould to allow injection of the casting material. Careful attention must be paid during this process to ensure the material will completely fill the mould, otherwise casting errors will be inevitable.
- The injection may commence and models will soon be in abundance.
Imperfections and Dangly Bits
There are three major side effects to the casting process: vents, flash, and mould lines. Vents are the dangly pieces on a metal or resin model that you can quickly nip off with a sharp knife or a simple twist and exist to allow excess material to overflow safely and air to escape during the injection. Flash occurs when the casting material squeezes between the mould's halves, leaving a paper-thin surface between the gaps in the finished piece. Mould lines occur when the two halves of the mould aren't perfectly aligned before casting. In some cases, they're subtle and easy to file down, while some can be so bad the model looks like one face has jumped half a scale meter to one side without informing the other face.
There's really no excuse for bad mould lines on metal models passing quality control when they can simply be melted down and recast. Resin, on the other hand, cannot be recycled in the same fashion, so resin casters need to hold themselves to a higher standard of quality (Quality, you say?).
Mold Wear and Tear
Due to the nature of the molds, they often cannot be used forever. They were forged at a temperature not much higher than the models themselves will be forged in, and so if a delicate balance is not maintained, the mold will warp, crack, or generally lose detail. Even when all possible care is taken, molds just don't last forever (nobody has yet told Airfix this). Model makers use several tactics for working around this:
The first and most straightforward is simply recasting the mold. More often than not, the "parent model" will be put in reverent storage and won't be melted away like in bronze casting, which is similar but different. The parent can be used to make more molds as needed. Sometimes, however, the parent is considered too precious, so a first-generation "daughter" model will be cast in the toughest stuff the model makers could possibly use (sometimes at the expense of the original mold) in order to make a very durable model which can be used to cast molds over and over without warping.
The second tactic is making a stronger mold. Sometimes the mold will get a mold made of it, and then that mold will be used to cast stronger molds which the models can be forged in without warping the mold.
Games Workshop and You
Games Workshop is a wargame company known for making egregiously overpriced models. If you didn't know that, you are obviously new to this wiki. They often excuse their prices by saying that their models are of exceptional quality and thus their molds are more expensive/break more often/need maintenance, despite that by industry standards (and as every single fucking 40K fan knows), Citadel miniatures have chunky details and low part counts, and price basic plastic models in the same range as top-of-the-line multimedia kits made for accuracy fiends who masturbate with digital calipers. And that's not even considering the fucking bubbles.
Casting can be expensive or cheap, depending on how you do it. A comprehensive fa/tg/uy-written guide is available to help you through the process.
As a side note GW likes to flail around its netsite claiming that it's illegal to take any and all copies of minis and make conversions. That is bullcrap since that goes in accordance to the country one is living in; in some European countries, for example, you are allowed to make as many copies of anything you have bought as long as you aren't selling or otherwise distributing them.
"And it was foretold in the book of The Second Machine Age that like a rising star a new science will come to be, and all men across the globe may print their miniatures, at affordable prices, forever ending the rule of the old powers and starting a new age of wonders."
This is GW's nightmare come true, the Doom Made Manifest, the Great Equalizer. 3D printing is a method of accurately fabricating objects using a 3D printer. 3D Printing works from a digital blueprint of the object in question, loading the material it will use, and then it fabricates the desired object before your very eyes. Originally, 3D printing was restricted to industrial purposes because of its sheer size and cost. By the 2010s, the costs have come down to the point where 3D printers are commercially available to the regular consumer and are relatively easy to understand and use, so even regular neckbeards like you and me could manage to use one. Printing a model is as simple as getting your hands on a 3D printer, its printing medium, and the file of the model you want; there's really very little stopping you from creating your own army without subjecting your financial status to GW's pricing horrors.
With this in mind, it is easy to see why GeeDubs would collectively shit themselves once 3D printing becomes a common thing everywhere, just as cars and cellular phones have; their monopoly over the miniature market would be completely obliterated in record time. In fact, it has already started, with some sites like The Pirate Bay hosting schematics specifically designed for 3D printing, including GW models. Thus, it is not that hard to imagine GW collapsing within a decade or two if they do not adapt to the times and change their marketing strategy (such as selling the blueprints and raw plastic).
What makes 3D printing so cheap is that it cuts production down to one step. Rather than following all of the steps above to make a model by hand, a 3D printer does all the hard work for you. Further, a 3D printer means you don't need to spend money on molds; if you've ever wondered why Forge World is so expensive, one part of that is because resin is cast differently to plastic, so the molds wear down faster and have to be replaced more often, not really a problem for us neckbeards since we aren't making ten thousand parts, but for a manufacturer it is a notable expense. On the other hand, a 3D printer works from a digital master and has no need for a physical mould. Without a mould, there's no chance of all sorts of problems that injection casting faces. Lastly, a 3D printer uses much less material; models don't have to be cut for sprues and there's no injection nozzle to which material can stick.
While your imagination runs wild, keep a few things in mind while thinking about how many Mk.3-Armored Space Marines you want in your army compared to how many Mk.4's. Even as of 2015, 3D printers are still quite expensive, at least several hundred dollars for a printer of any quality (or a seed printer if you want to print more printers). Printers use spools of plastic feed, glues, or several kinds of urethane powder, which can all limit the materials available for your models. The last thing you want is your glue melting your Fire Prism or not adhering to your Warjack, and let's not even talk about paints. Also, all that plastic is expensive; not GW expensive, but still notable. Unless you are so seriously addicted to your plastic crack that you know every kind of commercial plastic by heart, you might want to do some research to figure out which printers can use what plastic before you buy. And most importantly, as of 2014, 3D printers that a fa/tg/uy could buy can't print at a high enough resolution to look good at 28mm scale by any stretch of the imagination. If you thought OG Finecast was bad, making a 3D print of anything tabletop scale on one of those is laughable.
On the other hand, the metal-printing industrial jobs can make jet engine turbines and artificial fingers. So that's cool, we may still feel bad about some of the good designers and writers at Games Workshop who may end losing their jobs, although for all the piracy on the world Black Library is still kicking, so who knows in the end, or maybe they just can reconfigure their model the way MiniWarGaming did when they no longer couldn't sell minis due some changes enforced by certain general manager.
- Memo by a 3D-printing fan: It's true that MacGyverable 3D printers at acceptable prices are too inaccurate to make anything smaller than a Killa Kan without looking like "thin your paints" on the plastic level, generally because they don't handle curves or overhangs very well. However, for the boxy vehicles that make up most of 40k, it's perfectly adequate, especially when printed in certain ways that, while requiring assembly later on, maximize straight vertical and horizontal surfaces for the singular parts being printed; in these cases, the differences may be unnoticeable. On top of that, plastic prices for ABS, the most commonly used (and efficient) plastic in use in the 3D printing community, is about 20$ per pound. Go ahead and weigh your Land Raider, or hell, your entire collection of armored vehicles. Wanna bet you could make eight times as many tanks as you have right now for ten bucks? Imperial Guard tank lists say "Hello."