Cels Forum

I'm not if this works with acetate, but it 
does with plastic.

This is a little trick I learned as an antique restorer.

For plastic, take an iron and place it on 
the lowest setting. Place the area of your cel that
is creased on an ironing board and then take a towel and
place it on top of the crease. You then very quickly run 
the iron over top of the towel.

I would take a piece of acetate and test it with your iron
to see how much heat it will tolerate. If done the wrong
way, the acetate can melt. This trick also works with
creased paper.

I hope this helps!
Deb