Undesirable sticking together of two painted surfaces when pressed together (e.g., a door sticking to the jamb).
Not allowing sufficient dry time for the coating before closing doors or windows.
Use of low quality semigloss or gloss paints
Use top quality semigloss or gloss acrylic latex paint. Low quality latex paints can have poor block resistance, especially in warm, damp conditions. Follow paint label instructions regarding dry times. Acrylic latex paints generally have better early block resistance then vinyl latex paints or alkyd or oil-based paints; however, alkyds develop superior block resistance over time. Application of talcum powder can relieve persistent blocking.