Resin Casting Miniature

Resin casting is a replication process, not a molding process in the tooling sense. A finished master is suspended in a silicone block, the silicone cures around it and is cut open, and each production piece is then poured by hand into the resulting cavity as a two-part liquid resin that cures rigid. There is no metal tool and no injection pressure. The consequence is that the same master can go from approval to a first sellable cast in a few days, and the surface detail is limited only by the master and the silicone, not by what a steel tool can flow. The trade-off is labor: every piece is poured, demolded, trimmed and inspected individually, so unit cost falls with volume far more slowly than on an injection process.

We run resin miniatures from 28 mm tabletop gaming scale up to about 150 mm display figurines, which covers the range where hand casting stays economic and detail stays legible. At the small end, a 28 to 32 mm figure is roughly 30 to 35 mm tall including its base, and detail at that size has to be designed with the paint in mind rather than the sculpt alone. At the large end, 120 to 150 mm is where a resin piece starts competing with rotocast vinyl, and resin wins on surface detail while losing on weight and drop resistance. Above roughly 200 mm the silicone mold size and the resin volume per cast start to make rotocast vinyl the better route unless the piece is a sectional kit.

Bubbles come from three sources and each has its own fix. Air whipped into the resin during mixing is removed by vacuum degassing the mixed resin for 60 to 120 seconds before pouring. Air trapped in the mold cavity, especially in undercuts and thin extremities, is handled by pouring in a thin stream, tilting the mold, and using a pressure pot at 40 to 60 psi during cure, which compresses any remaining bubble until it is invisible. Air drawn in at the mold seam or through a thin section is a mold design issue, fixed with vent channels at the highest points. A supplier who quotes low-cost casting without stating a degassing and pressure step is telling you where the bubbles will show up, which is usually the face.

A platinum-cure silicone mold typically yields 30 to 80 pulls before the cavity surface starts to degrade, and the degradation shows first as a loss of fine detail and a dulling of sharp edges rather than an obvious failure. Tin-cure silicone runs shorter and is cheaper. That is why a resin edition is genuinely limited by the tool rather than by a marketing claim: a 50-piece numbered edition in a single mold is a coherent product, while a 300-piece edition needs three to four molds made from the same master, and we quote those as separate tooling lines so the edition cost is visible. We record the rated pull count for each mold and replace on schedule rather than waiting for visible degradation.

Total production runs 54-75 working days, though a small silicone edition can complete much faster once the master is approved, because mold making is 3 to 6 days rather than 12 to 18. The stages are: reference and 3D sculpt in 5-11 days, printed master and prototype approval in 7 working days, silicone mold making in 3 to 6 days, casting and painting in 20 to 30 days depending on quantity, and QC and packing in 5 to 10 days. Sea freight adds 25-40 days and air freight 3-5 days.