Quilting rules are 1/4 inch thick so you have the proper rulers....rotary cutting rules are about 1/8 inch thick and not thick enough. I don't know what machine you have. There are different types of feet used for long or mid arms. I have an APQS machine and need to use the thicker ones for ruler work and I have thinner ones for free motion work. I would check with your machines dealer to see if they have a specific foot to use. It would help if we knew what machine you have as someone here might know what you need.