Rosco makes a range of gels

http://www.rosco.com/filters/cinegel...V&CategoryID=2


I would need to expand my range of existing gels, I just converted to the MagMod system and it may be sometime before they are able to expand for a limited market, so I would need some sheets of gels that I could cut to fit the system. Do you have any resources here.

Also If I use stacked gels, how would I do that calculation.