A custom logo button or scarf ring is a die-casting program, not a colourway of an open-line SKU. The metal is usually Zamak 3 (a zinc–aluminium–copper alloy, ASTM B86 / equivalent GB grades). The tool is steel. The calendar is measured in weeks, not overnight sampling.
What to send before anyone cuts steel
A STEP or IGES solid, a 2D with tolerances, the annual quantity, the finish, and how the part sits on the garment (sew-on shank, rivet, glue, split pin). The caster’s DFM will push back on:
- Wall thickness. Zinc likes roughly 0.8–3.0 mm. Below about 0.6 mm, fill and distortion become a gamble.
- Draft. About 1–1.5° outside, more inside, or the part scuffs on ejection.
- Deep pockets that trap air.
- Finish: a high-gloss plate needs a better as-cast surface than an antique.
Zamak 3 melts far below aluminium, which is why tools last (often cited in the 200,000–300,000 shot range with H13 / SKD61 at a sensible hardness). That life only matters if your quantity is real.
The shop-floor sequence
Mould design covers gates, vents (too deep and you flash; too shallow and you trap gas) and cooling on thick bosses. T0 is the first shots: short fill, cold flow, sink, ±0.1 mm on a small fashion part is a conversation, not an automatic reject. Zinc shrinks on the order of 0.6–0.8%; the tool is cut to allow for it.
A 100–500 piece pilot checks whether the process holds. Typical order-of-magnitude parameters you will hear: die temperature around 180–220 °C, intensification in the tens of MPa, cycle under a minute. Then plating — which is a second factory — and only then a wear or salt-spray test on the finished piece.
Money and time
Expect weeks for the tool, not days, unless you are recutting an insert. NRE is a line item. Amortising it into a 300-piece fashion order makes the unit price look absurd; that is arithmetic, not greed. Open-line hardware exists so that brands who do not need a private logo do not pay for a cavity.
If the design is still moving, stay on 3D prints or an existing mould and change only the plate. Cutting steel for a logo that marketing will redraw is the most expensive trim in the collection.