Paint dripping edge on the wallpaper
If you want to make a wall colored, e.g. of course with a border strip on top of the ceiling or decorative stripes in different colors you stick with masking tape off.
However, the masking tape is not exactly on the wallpaper, especially in rough-textured wallpaper, so that the color runs quickly under the masking tape and forms ugly color noses.
This can be prevented if one gives about the transition from masking tape to wall acrylic (from the hardware store / spray gun). Simply "smear" over it with your finger. Acrylic can be painted over, so it takes on the exact color, on the other hand it seals itself off bomb-proof, resulting in a straight color line.
