Have you intended to get started with a Diamond Painting just to notice that there is no glue on some parts of it? Sometimes the glue gets stuck on the protective plastic and if that happens you can usually put the plastic back on and push on it. Then the glue usually sticks to the canvas again if you are lucky. In cases where the glue is gone and not sitting on the plastic, I have some tips below. If you have any good tips, feel free to share them in a comment below.
This tip is suitable if you do not have a large area that lacks glue. You can paint a thin layer of transparent nail polish on the canvas to make the drills stuck. Remember not to paint a too thick layer because then the drills will end up in different heights. Which will not look good when your painting is finished.
You can also use different glues. One that becomes transparent when it dries should be the best. Just make sure not to have too much so that the drills ends up being different in height. It is also possible to use glue for nails and glue sticks.
If you have a large area where the glue is gone, you can use a thin double-sided adhesive tape. It is important that it is thin so that the drills do not end up too high against the others. Otherwise, the painting will not look particularly good when it is finished.