I painted newly wallpapered walls with white color (2 times). Now I want to paint a rectangular part of the wall in a different color. To accomplish that, I used tape to get exact, well-defined outlines.
The problem is: Removing the tape also removes (parts) of the white color underneath.
How can I apply the white paint such that it won't get removed when I pull off the tape?
I would guess that your issue is that you didn't prime first.
From Wikipedia:
A primer or undercoat is a preparatory coating put on materials before painting. Priming ensures better adhesion of paint to the surface, increases paint durability, and provides additional protection for the material being painted
You buy primer from the same store you would buy paint. Primer goes on first, dries, and then you paint your final color on top.
The original white paint was dry to the touch, but not dry. It takes a solid month in a low-humidity atmosphere to allow the paint to dry fully. Even then, I would use a low-adhesion Frog-brand tape to create that line. Regular Frog or Scoth Blue tape can be used for a surface that's been drying for a much longer period of time.
