I'm all take and no give these days. We have almost collected enough bottle caps to do a mural...so much for having enough by earth day...oh well. Anyway the mural is going to be inside, hanging on the upper wall of the library and will hang for at least one year. We are looking at about a 6ft x 5ft mural. So I need your experience in choosing the base for the mural and the attachment method. I think I have ruled out foam core as being too flimsy but I worry that plywood will be really heavy. Is there an in-between material we can use? Do we really need to drill each cap in or can we use hot glue...how about gorilla glue or liquid nails? Did you assemble the mural or have adult volunteers or have student's do it? What types of attachment materials did you let the students use (hot glue gun, power drill?) I will have 6th-8th graders who can work on this project. Thanks so much for you ideas. I know there are tons of posts about this topic out there but honestly with baby demanding all my attention I don't have time to search through everything!