The starting condition decides the primer. Paper-faced drywall and acrylic or latex paint absorb too little for lime to hold, so the selected product’s primer system goes on first. Fresh drywall is usually sealed with a drywall primer, then given a mineral or bonding layer; painted walls in sound condition often need only that bonding layer. Tinting the primer near the final color keeps thin spots in the limewash from flashing white.
Before primer, the existing paint is tested for adhesion, grease and dust are washed off, and damage is filled and sanded. Glossy enamel may need scuffing. Peeling or chalky paint has to be removed or consolidated, because a lime finish can never be more secure than its base. Some limewash lines are formulated for unpainted masonry alone and are never used on drywall.