HOLDEN’S HX-STIFFENING AGENT is a one part, low viscosity, pourable liquid that, when mixed into a casting or mask making latex, will increase the stiffness and reduce the flexibility of the cured latex. Varying levels of stiffness can be achieved in proportion to the amount of HX-STIFFENING AGENT added. HX-STIFFENING AGENT is compatible with HX-200™ Casting Latex, HX-407™ Mask Making Latex and HX-807™ Brushable Casting Latex. These products are used only when casting into a gypsum mold. HX-STIFFENING AGENT offers versatility and control when using Holden’s Latex products to make hollow cast objects, puppetry, theatrical scenery, mask making, etc.