On Fri, 12 Feb 2010 15:19:18 +0000, fred wrote:

You don't need much, just a light spray. I've used the other 3M product
Spraymount which stays repositional but I've found it fine for long term
holding.


The blue 3M Spraymount allows repositioning and tends to come unstuck
after a few years. The red 3M Spraymount does not allow repositioning
but gives a permanent fix.

You need to go to a craft or art supplies shop for the red stuff,
whereas the blue stuff is far more widely available.

Back to the maps; I would use red Spraymount to stick them to
foamboard. That's a rigid plastic board that is widely used for this
exact purpose in exhibitions and displays.

It is available from good art shops.