Using grid lines on cutting mat?
 

I am left handed and lay my fabric on the mat and use the lines on mat to line up my fabric and lay my ruler down on the mat and line the ruler up with the lines top and bottom of the mat to cut. A person at the guild told me never to use the lines on the mat to measure. I have been doing my cutting this way for ever. Is this wrong? I don't know how I would do this otherwise. Thanks for your help.

I use mine in that fashion too. I've measured the lines on the mat against the ones on my rulers, and they're the same, as they should be.

I have also heard not to use the lines on the mat as they may not be accurate, but...I still do, I learned that way and it is hard to teach an old dog new tricks.

I use mine all the time. If it works, it works. It's just another of the many things some people will say "never" do or "always" do. You've got to do what works for you. If you are happy with your results, why change?

It sounds like it is working fine. I wouldn't worry about it. The only problem might be if the measurements weren't right on the mat, and I think that would be unlikely.

Dina

Thanks for all the your answers. I am an old dog and thought, I am not going to start over , if it works.

Do you have problems that may be caused by the way you cut your fabric? If not do it the way you want! I use the lines on the ruler as much as possible because cutting on the same line on my mat can cause problems to my older mats. putting cut ridges in or even removing some of the lines by cutting away small amounts every time you cut. (these are not self healing mats, I've never had one of those) just remember to keep the fabric you want to use under your ruler. If you are cutting left handed keep non used portion of fabric to your left. line up correct line on ruler with the raw edge, an make your cut like always. Just do what works for you and enjoy the process!

My personal opinion is that if you are consistent with the way you cut, it should all come together perfectly! If you were to use 2 different ways to measure and cut, then I can see some problems arising.
JMHO

Your ruler is more accurate. You should use two rulers to square up your fabric then cut using your ruler not the mat grid.

Compare the measurements on the rulers you use to those on your mat. If they are the same you have no potential problems. And as has been mentioned already...if you aren't having problems with your blocks fitting together you are probably doing ok.