As a general rule try not to paint over wallpaper😄
Most often, I recommend removing wallpaper, so you can start with a fresh wall, If this is not an option then there are many issues to consider before you paint over wallpaper – keeping in mind the points stated above.
If removal of the wallpaper is not an option, the first thing you want to do is to clean the surface then lightly sanded seems to make them as smooth as possible. Ultimately you want a clean dry roller and a smooth surface prior to application.
🛎 Test a quick drying latex adhesion promoting primer, there are many wallpapering Products out there – check out with your paint supplier to see the recommended system. If the primer drives without lifting and blistering, clean the surface with the paper then the surface is ready to be primed and then top coated with a good quality latex paint
🔖 note – the seams may be visible in some areas – repair those areas as needed.
📌 The seams may not lie down properly
📌Moisture from the paint could cause wrinkling blistering or peeling
📌The texture from the wallpaper on a Telegraph through causing a poor look on a solid wall
Any of these things could cause problems for those reasons We always recommend testing the system prior to taking on the entire job, a test can prevent so many issues from occurring.