answer:You need different kinds of glue for different jobs and materials. You are not going to find a all in one glue that is worth its salt. For plastic I would go with rubber cement, for gems or stones you could use super glue, contact adhesive is good for materials and paper. I would suggest looking at packages, reading what it says, and selecting a few different glues, and give up on the idea of finding a universal one that does the job. If there really was an efficient glue that works on all materials, then it would be the only kind of glue you can buy, as it would have long crushed any competition, just on word of mouth alone.