Hi girls
the pink ATG gun only takes 6mm tape. the yellow gun takes 19mm 12mm and 6mm with an adapter..
I love my ~ATG gun. have used loads of double sided tape for boxes and 3D cards only to find a couple of months later they have come apart.. don't have this problem with the ATG. I have 2 one for 12mm and one for 6mm although 6mm is my preference.
as for other glues.. I use Hi Tack fact tack glue, its a bit like pva but better, goes on white dries clear is flexible and sticks almost anything.
when sticking on tiny gems squirt a little bit onto scrap paper and use a cocktail stick to put the glue on the gems.
hope this helps.