I bought some Friskar brand blades for my Olfa 60 mm rotary cutter and they cut just fine. Seems to me they were 1/3 the price of the Olfa brand blades at Joanne's. Just for the heck of it, I marked the date on the last blade to go on the cutter and it's still going strong. That date was 3-11-11 and have cut 6 to 8 quilts plus gobs of 3 1/2 inch squares my quild uses to make 9 patch blocks for wounded soiders.