Things You'll Need
If all else fails, apply a dab of coconut oil or vegetable oil over the adhesive with your fingers, using as little oil as possible. Dab the oil away with a soft, lint-free cloth, and use another section of the cloth to rub the adhesive residue away. Any kind of oil may stain a wall, so test it in an inconspicuous area first and use it only as a last resort.
Handle the putty knife with care to avoid scraping the paint or damaging the wall. The more parallel the blade is to the wall, the less harm it will cause to the finish.
Even masking tape leaves residue behind if it is left on the walls for months or years on end. Remove masking tape as soon as it is no longer needed to avoid the problem.
Tape is a speedy, simple way to hang paper or posters on a wall, but removing the tape and its adhesive may be anything but simple. Unless the tape is designed to peel cleanly off a painted wall after use, as is the case with painter's tape, it tends to leave adhesive residue behind, especially if it has been on the wall for a while. Several different methods may be required to remove the sticky substance completely. Whenever possible, skip harsh chemicals that may damage or stain the wall paint.
Pick at the adhesive residue to remove as much of it as possible with your fingernail. Rub your finger back and forth over the sticky substance to lift it from the wall. In some cases, the adhesive becomes gummy and sticks to itself as you rub and roll it away, much like rubber cement.
Scrape away some of the residue with the edge of a putty knife by holding the tool nearly parallel to the wall so the blade is at a slight angle, touching the wall. Slide the blade across the adhesive to help lift it away. Scraping in this manner also removes small bits of tape stuck to the adhesive residue.
Heat any remaining tape adhesive with a hair dryer set to warm until the adhesive softens and becomes gummy. Allow it to cool slightly and roll your finger across it to peel the adhesive off the wall. Run the putty knife blade over the adhesive to help pull it up if the adhesive feels thick. Continue heating, rubbing and scraping the adhesive until it comes off completely.
Kathy Adams is an award-winning writer. She is an avid DIYer that is equally at home repurposing random objects into new, useful creations as she is at supporting community gardening efforts and writing about healthy alternatives to household chemicals. She's written numerous DIY articles for paint and decor companies, as well as for Black + Decker, Hunker, SFGate, Landlordology and others.