It comes in a small, white bottle with an orange top. The front side of the bottle is blue and reads the product's name at the top in white text.
As its name states, Forever Glue has the ability to stick anything together forever. However, it can be washed off with tears, as revealed at the end of "Stuck in the Wringer." Therefore, it really is not "forever" glue at all, just strong, regular glue at best.
After SpongeBob gets stuck in his wringer with no sign of recovery, he asks Patrick for help, though the latter only makes matters worse by using his Forever Glue to "help." Throughout the rest of the episode, SpongeBob is forced to go out in public with his wringer stuck to his body.
However, near the end of the episode, when SpongeBob and Patrick cry as a result of their friendship being brought into jeopardy, the glue dissolves and is thus revealed to not actually be permanent.