Creating plastic props and parts is a big part of costume making. Many costumes, from flashy superhero wear to grand historical garb, require pieces that may not be readily acquired in their original materials. For example, a large piece of gemstone jewellery or a gold badge would be expensive to reproduce, so many costumiers opt instead to make plastic reproductions. The best material for making plastic items like badges at home is resin, a liquid product often used in toy manufacturing.
Find a mould for the badge style you want to make, or create your own using liquid latex. To do so, sculpt the badge design in a water-based clay, then paint liquid latex directly onto the clay. Once the latex has dried, pull it away from the clay.
Coat the inside of the mould with a spray can of mould release agent, which will prevent the resin from adhering permanently to the mould.
Suit up for some serious resin work. Put on a vapour respirator to protect yourself from fumes. Wear latex gloves, long-sleeved clothes and safety goggles to protect your skin and eyes from resin contamination. Bring your supplies outdoors or into a well-ventilated workroom.
Fill a plastic cup with laminating resin and add the catalyst. Check your product's packaging for brand-specific ratios, or use the chart in the Resources section to determine your own ratio. Stir with the plastic spoon until well mixed.
Fill the mould with resin and leave it for at least 48 hours.
Open the mould once the resin has dried and pull out the badge. It will feel like a hard chunk of plastic.
Put your safety goggles back on and wear a particle respirator. Sand down the surface of the badge until it is as smooth as you like.
Polish the badge with auto wax or paint it as desired.
Hot glue a pin back onto the back side of the badge. Be careful not to melt the resin.
To prevent damage from resin spillage, cover your work surface with plastic. If you would like to make your resin coloured without painting it, add resin pigment when mixing the resin.