what's wrong?
 

I have changed the mat and the blade in my rotary cutter but still having trouble with not cutting all the way through 4 layers of cloth. It should be cutting like butter but it's more like perforations and Very frustrating! Can rotary cutters wear out, too?

Did you tighten the screw too much when you put the new blade on?

Try turning the blade over. Some rotary cutters have a right and left hand way for the blade.

also, make sure you only have one blade in the cutter! Ask me how I know.

All the above suggestions are good ones. I don't think the cutters wear out.

Been there. Done that. That's why I like Sewology blades... package of five come in individual wrappings. So good for a silly little old lady. :)

I can attest to that !

I had a Fiskars cutter that did. The spindle cracked, and the blade got jammed there and wasn't turning. So while it did cut, it was like cutting with a box knife.

Interesting, IceLeopard. I didn't think they did.

More than once, I have changed the blade and put two in instead of one blade.