Abstract: A rotary cutting mechanism for the accurate, repetitive, controlled, pattern spacing of slits in thin flexible sheet material. The mechanism comprises a pair of rolls with one of the rolls having a plurality of blades spaced at intervals about its circumference. Each blade contains a plurality of cutting edges. The other roll has a plurality of platen bars spaced in a manner to cooperate with each cutting edge. Both of the rolls have steel bearers mounted at their ends with the bearers on the rolls having the same diameter as the outer edges of the cutting edges and of the platen bars to precisely control the cutting action of the mechanism.