Paint must be dry and cured for up to four weeks before hanging wallpaper over it. Drying time depends on the type of paint, the number of coats, humidity and air flow. If wallpaper is applied too soon, the paint may bubble, causing the wallpaper to not adhere properly.
Most paint dries to the touch within a few hours, but takes longer to cure. Oil paint is ready to wallpaper after seven days, while latex paint takes up to 30 days. Oil paint provides a more stable base under wallpaper than water-based paint. Primers specifically designed to be used under wallpaper are the best choice for a wall that is to be wallpapered..