Love this tip from American Patchwork Quilting.
 

Was reading my new magazine the other day and a tip was to use the nonslip shelve liners ( they cut one out of a heart in the pic) and put under your ruler to stop the slipping. Well okay I didn't cut out of a heart, but I did cut a 2x3 rectangle and a 1.5 x 3 rectangle and gave it a try. No more of those little sandpaper dots on my rulers. This is amazing. I wish I would have thought of this long time ago.

One thing I do use though is painters tape, cut off a small piece, roll it so it's sticky all around and then put it either under fabric, but mostly use when I'm making stencils out of plastic. It really holds the fabric too.

Great tip - I'm going to give this a try (might have to cut a corner out of a shelf liner I have now). :)

Do you mean the kind of shelf liner that is bumpy and rubbery?

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Yes, I bought a role from the Dollar Tree to use under my sewing machine.

This is great tip, but these don't have sticky backs so did you glue it?

I will give that a try when my grippers stop working. Maybe use double stick tape to hold it to the rulers.

thanks for the tip

I've been using the shelf liner for quite some time. Also mentioned it on this board. Just saying. I lay a strip across the material. I also use it to grasp jars to open.

You don't need glue or anything to hold the liner or ruler down. Stays put til you move it. Also helps to keep the ruler from moving if you need to cut multiple layers of fabric.

Good idea and well worth a try! Thanks for sharing this tip.