Flex Base can be applied clear or mixed with pigment (pure pigment only, not blends) and can be applied with a brush, spray gun/airbrush, or foam. Crosslinking basecoat is not mandatory but is recommended. Basecoats that are crosslinked need to have a topcoat applied before the crosslinker in the basecoat is fully cured. The cure time depends on temperature and humidity (will cure faster in warmer, drier temperatures).