I am decorating my room to our new house we just moved into. I would like to take the one wall and put pictures across it without any frames. I have tried tape and it just messed up my walls, and I definitely can't use glue. I was wondering if anyone had any suggestion of something I could put my pictures on the wall with? keep in mind I am talking 80 pictures and I would like them to stay there a long time.
Depends on the sort of wall: wood, painted plasterboard, wallpapered etc.
Map pins and other small nails leave tiny holes that are easily recovered during repainting, and are unnoticeable in wallpaper or in wood paneling at joints.
That said, any picture left for a long time will cause changes in the appearance of the wall because it shields the wall from washing wear and UV, which fade the surface, and from grime (e.g. cooking condensates, tobacco smoke) which tend to yellow the wall.