Uncovered foam as a finished texture can also be a successful option depending on the design. Using dye as a means of coloring foam is much better than paint. Paint only sits on the surface layer, whereas dye goes all the way through the foam and becomes intrinsic to the piece. Paint can also make foam stiff when too thick. Dye, on the other hand, since it is a stain, will maintain the flexibility of the foam. Hand painting using brushes and sponges is a good way to apply color to foam. The airbrush is a handy tool. It can be used for adding shear, translucent layers of paint like a dustcoat, or it can be used to apply opaque layers of color. If painting open-celled urethane foam or closed-cell foam, airbrushing is one really good way to apply color.