Don't know what I'm doing wrong but I try to be careful, use sharp blade on rotary cutter along straight edge and it won't cut through the 2 layers of fabric! I end up going back over it and usually mess it up badly so I have to straighten edge and start over! Any hints on cutting a perfect straight edge?

check your rotary cutter.. You may have two blades stuck together. I happened to me and s it took a little while to figure that out. those blades sometimes stick together and you can not get a decent cut no matter what.

New blades are VERY hard to get apart if there are multiples in a package. I agree that it sounds like you have two in your cutter.

Also make sure blade is loose enough that it is rolling.
Good luck !!

All good advice, don't forget to unlock your blade.

Two blades is the first thing I thought of. One way to get them apart is to stick a pin between them.

If that isn't it, then you might be using one of the older cutting mats. I have two odler ones that are white, and they don't allow me to cut through everything like the newer self-healing mats do.

It's got to be one of those two things. You came to the right place to talk about this! :thumbup:

I just had this problem, and it was two blades stuck together that were messing me up. I was SO frustrated! Don't know why I didn't figure it out sooner?

put cutter blade snuggly beside ruler, apply down pressure- roll up length of ruler- away from you=
a little pressure is necessary- people tend to be a little afraid of their cutters at first- after awhile you will know how hard you need to press down to get a good cut- not very hard- but some pressure is necessary---and first check to make sure you have only one blade in...even Alex Anderson one time (on her television show) had 2 blades in and problems--trouble shooted on the air...good lesson...

As mentioned check for two blades.

Also, check that you have the blade on the correct side of the cutter. It's easy to put it back together wrong.

And try a new blade, just in case it's a bad blade.

put pressure down when cutting
are u standing or sitting when cutting better to stand and cut
are u helding your ruler tight enough so that u have the edge for leverage

just my thoughts :D :D :D