I used to have trouble finding the right type of glue for collages, and I wonder if others have had this trouble too. If I gave them bottles of Elmer's glue it often would end up in puddle size blobs all over their paper- it would run, it would drip, it would spill over the edges as I took it to the paint rack, and in the end the collage "materials" would slide right off the edge with it. Glue sticks didn't always keep things on the paper, especially weighty things like shells. Paste was sometimes not the greatest to work with- stick materials to their fingers rather than their papers and not easily be moved to the papers, and would create globs all over their paste, that when dried looked like a clear version of something that might come out of their noses. (I apologize for the unpleasantness of that last statement, but it is true).
Finally, I came up with this idea: I put Elmer's glue (we buy it in huge bulk containers) in paint cups for them and added a little liquid watercolor and paint brushes.
I put it on the table with whatever materials I had for collages.
The materials above include mixed dried beans, buttons, colored pasta, scented rice, and a plate of sequins, beads, foam shapes, shells, little wood pieces, and other random things from the dark depths of the bottom of my collage bin. Of course there are hundreds of options for collages; Although I really like to give them a variety of materials for them to use as they want to, it is very easy to do theme collages for theme type teachers; For Valentines day I recently saw some cute collages done with heart sequins, ribbons, heart buttons, and heart foam shapes. (For instructions to make scented rice and colored pasta- see my entry here).
This truly has worked better than any glue substance that I have used yet. I have been using it for about a year now.
They spread it over their paper in reasonable amounts (without any guidance) and it held everything to their papers.
Some of them actually use it like paint and then just put a little button here, a little paper there, but this also comes out looking very nice.
(Here is a picture of some voluntary sorting one of the kids was working on today that I couldn't resist putting up).
As far as clean up goes, soaking brushes and cups gets the glue off nicely, and works for the table too, although if you let the glue dry on the table it peels up in big pieces which can be fun- the kids always help me do that.