Trouble in use

Glue sticks ：Why doesn’t the glue stick properly

There can be several reasons why glue does not stick proerly:
1. The application amount is too little.
2. The coated surface became too dry after a while.
3. The liquid glue is too dry.
4. The glued area is too small for paper.
5. It lacks power to hold the parts, or the time is too short.
6. The material of paper is too hard.