Resin Doll Kits

Resin casting is used to produce collectible and customized toys and figures like ball-jointed dolls, as well as scale models, either individual parts or entire models  They are generally produced in small quantities, from the tens to a few hundred copies, compared to injection-molded plastic figures which are produced in many thousands. Resin casting is more labor intensive than injection molding, and the soft molds used are worn down by each cast. The low initial investment cost of resin casting means that individual hobbyists can produce small runs for their own use, such as customization, while companies can use it to produce small runs for public sale.  Our resin doll kits are produced in small quantities.  This is the process to make resin doll kits.

They started with the traditional sculpting process where Karen William Smith designs a clay sculpture. Where appropriate, for example when making a doll kit, the sculpture is dissected into several parts like head, torso, arms and legs. A flexible mold made from room temperature vulcanized silicone rubber (RTV) is made for each part.

After the mold has been made a synthetic resin – commonly polyurethane – mixed with a curing agent is poured into each mold cavity. Mixing the two liquid parts causes an exothermic reaction which generates heat and within minutes causes the material to harden, yielding castings or copies in the shape of the mold into which it has been poured. The molds are commonly half-divided (like the hollowed chocolate Easter eggs with candy inside) and a release agent may be used to make removal of the hardened/set resin from the mold easier. The hardened resin casting is removed from the flexible mold and allowed to cool.

Due to aggressive nature of most compounds used for casting and the high temperature of the reaction the mold gradually degrades and loses small details. Typically, a flexible mold will yield between 25 and 100 castings depending upon the size of the part, the intensity of the heat generated.

Depending on the type of product it may then be cut or sanded to remove any casting artefacts like sprues and seams. Some products are also assembled and painted, while some models and kits, which are intended for the consumer to assemble, are left unfinished.

The ability of RTV silicone molds to reproduce even the tiniest detail means that many of these low volume castings are of very high quality. The ability of almost anybody to produce plastic castings at home, with a very low monetary investment, has resulted in some terrible quality products as well. Quality of both original masters and resin castings varies due to differences in creator’s skill, as well as casting techniques.

Our new kits are coming soon.