How an accidental discovery led to this temporary paint you can peel off your wall

Unpaint is formulated to peel directly off a variety of surfaces.

In 1968, a failed adhesive formula developed at 3M resulted in tiny yellow notepads whose individual papers could stick just about anywhere. The Post-it note is perhaps the most popular of all the genius accidental products that have become staples of our lives, but there are others, too—from penicillin to Velcro to SuperGlue. Now, there’s another to add to the list.