I am a teacher bless with working in a new school. My classroom has painted brick walls though which make hanging posters and student project challenging, and I also have 2 outer walls. Does anyone have any suggests on how to do this? We've tried masking tape (which falls off when warmed), foam tape (which leaves sticky residue or tears the projects), and hot glue (which can also tear projects). This is such a teacher's nightmare! Any other ideas which might help are so welcomed!