Does anyone use Rosco filters in place of Kodak Wratten filters? The larger size, like 5x5 and 6x6 inch, Wrattens are hard to find in good condition and the few NOS ones that are available on eBay are quite pricey at over USD50. A 20x24 inch sheet of Rosco material is well under $20. I don't know how the Rosco material compares optically with a good-condition Wratten, has anyone tried substituting Rosco for Wratten?