Paint blocking is an adhesion problem that occurs when two freshly painted surfaces stick together when pressed against each other. This often happens between a door and frame if closed before paint has completely cured. When separated, the paint may peel or leave a mark.
One way to prevent paint stickiness is to place wax paper between the door and the door jamb. The wax from the paper creates a barrier between the two surfaces. Don’t immediately stick the paper in the door frame. Instead, wait for the door to dry for one to two hours. Then place the wax paper between the two surfaces before closing the door for the night. Another wax method is to rub a white candle over the edges of the door after the paint dries. This gives the freshly painted door some protection from the newly finished jamb.