I had the v problem using it too. I figured it out to work for me. The black lines on the bottom of the ruler above the slots has to be lined up even on both ends of the fold. If the bottom of the fold is on top or the middle or the bottom of the line on the right side it has to be in the same spot on the left side. When I get the measuring line lined up on the fold at the same spot on the line I then cut the straight edge and then start cutting strips. I don't cut more then two layers or I'll get the V.