Bond It Plasterers' Pre-Grit is a high-quality, ready-to-use primer and bonding agent for plaster, specially formulated for internal use. This one-coat plaster bonding agent and primer contains added sand and aggregate which provides an optimal finish on smooth, non-porous surfaces. With a phthalate-free formula, this plaster primer pre-grit has a yellow pigment to allow easy identification of treated areas.