Masking walls and trim effectively on your next painting job isn’t as easy as it looks, and ordinary masking tapes are the biggest reason why. That’s why success depends on understanding the challenges involved and how to face them.
A particularly good example of tape that actually works is something called ScotchBlue Painter’s Tape. It’s made by 3M, and my tests show that ScotchBlue eliminates all traditional masking tape problems in an admirable way, and the adhesive is one reason why. You still need to seal the edges with your fingernail or flat tool to activate the sealing action, but as long as you do, paint certainly stays out.