Here are 2 methods for achieving a good matte, paintable surface on rigid, urethane foam. Both baby-powder and primer (sprayed into the mold and allowed to dry) may be used to create a cast part with a matte surface for easy painting. New Prime-it primer may also be used to simplify the painting process.
Get rigid foam here:
https://www.brickintheyard.com/collections/flexible-rigid-expanding-foams
Post time: Jun-28-2017