I am using the June Taylors rule with the slots for the first time AWESOME. I first bought some stencils from someone on QB, place stencil over back side of material with special washable pens, trace lines. remove stencil place another piece of material facing first material then sew. (this is for triangles) you get 32 at one time. After I cut ears and lay seams down I also use the June Taylor's slotted ruler and catch what I missed the first time. Perfect little triangle squares ready to sew. love it.