I have been looking for an earlier link regarding this topic and have failed to locate it. I know someone out there has done this and has been very successful. As a school we have collected hundreds of bottle tops and using an American book as inspiration we are about to embark on creating a whole school wall mural. However, the book instructs you to fix the tops using drills and screws but I am sure I have read somewhere that you can use glue, but not sure which one would stick plastic to plywood successfully and which can be used safely by young children. Please help if you can, either by sending me the link or advising me on the type of fixative to use instead of me having to use drills. Thanks.