The way I approached it with a couple of 'blow-ups which were too big to laminate was to get a roll of some of that self -adhesive transparent covering, cut a piece of hardboard ( which I then varnished to seal it) leaving a 'border" of about 2" using the hardboard as a backing plate mounted the pic and covered with the sticky plastic.
I made sure I left enough to wrap over the edge and it seems to be working OK so far.
I did also try map varnish but it discolours
G
