What is Primer Paint? Primer paint, otherwise known as a base coat or undercoat, is applied before your paint’s topcoat. Its primary purpose is to maximise paint adhesion to the surface and to ensure a long-lasting, smooth finish for many years. For harder surfaces that lack porousness, such as metal, primer is a must for proper bonding and coverage. Primers with stain-blocking properties are also … Continue reading What is Primer Paint? Paint Primer 101