Scotch tape was invented in 1925 by Dick Drew of 3M. It is a tape composed of clear cellophane with one side coated in a weak adhesive. The product was conceived to solve a problem of early spray painting; it was difficult to create distinct borders between two colored areas. At the time, this was acheived by affixing old newspaper to a surface which was to be covered. The new cellophane tape was used to mask areas that were to be spray painted. Generic brands are known as cellophane, or sticky tape. A similar low adhesive, though opaque tape for similar purposes is known as masking tape.
The initial versions of the tape were not sticky enough, and were prone to fall off. An auto spray painter believed the manufacturers were too stingy with the glue and told Drew to "Take this tape back to those Scotch bosses of yours and tell them to put more adhesive on it!" The nickname stuck, and the tape became known as Scotch(tm) brand cellophane tape. The mini tape roll dispensers sold by 3M even have a tartan pattern on them.