How do you fix ripples in wallpaper before painting over it. Do you cut out the wrinkles with a razor blade and use drywall mud over it and sand it down?

Best to strip the wall paper, then patch the wall (if needed), and then prime and paint. But if you want to just paint right over the old paper, I suggest cut out defects with a razor, spackle to make smooth, prime and paint.

After painting over wallpaper and not liking the vertical lines still visible where the strips of paper met, we decided to always completely remove the paper before painting. There are various products available at your housewares store to make that job quite easy.

If you are using a smooth surface paint, you will find it very hard to get a good finish over paper. Texture paint may work but the job will turn out much better with a strip off.

Remove the wallpaper... you have no idea what a gawd awful mess and how bad a wall with painted over wallpaper looks... and the near impossibility to go back and do it right.

Some idiot did that in the kitchen in my house before I bought it.....had to rip out all the old sheetrock and put new sheetrock up to fix it.