Spellotape

Spello-tape was adhesive tape used to bind magical objects that could not be repaired with a spell. Wands (such as Ron Weasley's) often needed spello-tape for repairs.

Behind the scenes
Sellotape is a British brandnamed cellophane adhesive tape. It is similar to Scotch tape in the U.S. This is an example of the numerous puns used in the books.