Temp vinyl posters falling down

[Texas_Signmaker]

I installed some non-perm adhisive posters on drywall in a gym. After two weeks one of the posters fell down. This is a large chain so I'm assuming this doesnt happen all the time. Is there a special way to install them? I used a felt squgee and tried to get the edges real good. Should I use heat?

 

[printhog]

if they stuck at first and then failed its likely the paint they're on. common problem with latex paints in any finish other than gloss.

http://multimedia.3m.com/mws/media/346473O/5-37-application-to-walls.pdf