How a Warhammer miniature is actually made

The first thing I did with my first box was scrape a line off a face. It ran from the eyebrow to the jaw, and I assumed I had been unlucky with the box.

I had not. That line is where two pieces of steel met, and no amount of quality control at the factory could have removed it. Here is the chain that puts it there, and what each step costs you at the desk.

Somebody drew it first

Games Workshop does publish this part. For Vashtorr the Arkifane there is a whole article walking from concept to finished sculpt, narrated by the designer who did it.^§ It is worth reading once, because it makes the obvious point that is easy to forget while filing a shoulder pad: somebody decided every one of these shapes.

What the studio does not publish is the tooling end. I went looking for a factory piece with steel grades, cavity counts and cycle times, and did not find one. So the second half of this post leans on general injection-moulding sources, and where it does, I say so.

The master, and what it costs

For its classic range Games Workshop has described the chain plainly. The factory keeps cast masters, sometimes metal and sometimes resin. Transferring from the original sculpt to that master loses a little detail, so a sculptor called Lewis cut the lost details back in by hand.^‡

Two things in that sentence are worth holding on to. Copying a shape costs fidelity every time you do it. And the fix was a person with a tool, which is not how anyone imagines a factory working.

The part has to be able to leave

This is the step that explains most of what a painter notices, and it is not Warhammer-specific at all.

Molten plastic goes into a steel cavity and cools. All thermoplastics shrink as they cool, and shrinking grips the steel. That grip has to be beaten, so every face running parallel to the direction the mould opens is tapered slightly. The industry calls it draft. Without enough of it, a part drags on the way out, scratches, bends, warps, or simply sticks.^†

The published numbers are small: half a degree on any vertical face, one or two degrees in most cases, at least three where the surface is textured, five or more where the texture is heavy.^†

Texture is the part I did not expect. A textured tool wall would lock the part in place, so the rougher the surface is meant to look, the more taper it needs. Every chainmail hauberk and every stone base on a plastic kit is a negotiation between looking rough and being able to get out of the mould.

And now the line on the face

The mould has to open. Its two halves have to meet somewhere. Where they meet, the finished part carries a seam, and the industry name for it is a parting line. It traces the path along which a tangent to the surface runs parallel to the direction the mould opens, and it cannot be eliminated from the process.^*

Only its placement can be chosen. So the mould line across your model’s cheek is not a defect and not bad luck. It is someone deciding that the cheek was a better place for it than the crest of the helmet, or that the tool had to open in the direction that put it there. Scrape it off without resentment.

The same logic explains the sprue itself, the gates where each part joins it, and why the cape is a separate piece: a shape that cannot leave the steel in one direction has to arrive as two shapes that can.

Five marks, five names, five causes

Once you know a mould has to open and the part has to shrink its way out, the rest of what you find on a sprue stops being random. The industry has a name for each of these, and a cause.

Flash is a small amount of material oozing into the seam, which needs trimming once the part has cooled.^** That is the thin fin you sometimes find along a mould line, and it is worth separating the two in your head: the line is where the halves met, the flash is plastic that got into the gap between them.

A sink mark is a dimple or shallow depression, caused by a cross section thicker than the rest of the part.^** If a shoulder pad has a soft hollow in the middle of an otherwise crisp panel, that is the plastic having cooled unevenly, not you having sanded too hard.

Drag and scrape lines come from not enough draft.^** The section above, showing up on the model.

A knit line forms where two opposing flows of material meet in the cavity.^** This is the one I would have got wrong. Depending on conditions they run from invisible to looking like a crack in the plastic, so a beginner can spend ten minutes filling a gap that was never a gap.

Gate vestige is the mark where the part was cut away from the channel that fed it.^** That is the nub at the attachment point, and it is why the flush cut matters more there than anywhere else.

What I am not going to pretend to know

Whether new Citadel miniatures are sculpted digitally. It is widely said and I found no Games Workshop page that states it, so I am not going to state it either.

What the tools are made of, how many parts one holds, or how long a run takes. None of that is published as far as I can find.

Whether the process above still describes a 2026 release. The article it comes from is about remastering classic miniatures, and stretching it to cover a new kit would be me guessing rather than them saying.