As far as I am concerned, the grippers on all the brands of rulers I have are not reliable. A few years ago, I got tired of my rulers slipping so I bought a roll of clear adhesive stair tread anti-slip tape. I cut it into pieces 1/4" x various lengths and attached short segments along the edges and down the center of the back of all my rulers and templates. It is very gritty and holds well, even over seam lines. Now with even light pressure I have stable rulers when I cut.