Another method that is very similar is
to 'tack' the poster with the same little rolled pieces of acid free tape
but instead of 'bagging' it, you can have it 'shrink-wrapped'.
OK , confession time again
. I've
done this a lot. When we had our retail store, we had a lot of college
kids that wanted a nice poster to put up in the dorm. They WERE NOT going
to pay the expense for framing but some were getting interested in collecting.
We've done literally 'thousands' of mini-sheets
this way. Having several colleges in town, we would get this problem every
September and January. We knew that they were going to nail or 'push-pin'
them on their walls so we would 'shrink-wrap' them on a slightly larger
board so it left a border all the way around the poster. Then we would
show them how to 'nail' the poster up by nailing thru the board border
and NOT the poster. By the way, it doesn't pop and tear the shrink wrap
if done right.