I was told by my friend that had owned a quilt shop to never use the lines on the mat - they're innacurate. She said to always use the lines on the rulers. That's what I do now and my piecing is much more accurate!!!

I only use the lines as a general guideline to keep things straight, but my ruler/ templates are what I follow & ALWAYS use the same ruler during a project, to ensure things are exactly the same. Believe me, they're not all even! If I have to change rulers (too long or short) in the middle of my project, then I double check it against the one I was using before. The only time I would rely on the mat lines is if it's a quick project w/ a lot of room for error.

Mom-6 says it so well. I use mine the way she does.

I use the line on the mat to lay my fabric straight, then use the ruler to measure my cuts. I try to use the same ruler for all the cuts. I really, really love the June Tailor Shape Cutter ruler, then I don't have to use any other lines.

The only time I use the lines on the mat is when I am squaring up the edge of my fabric to begin cutting. I always use my ruler for any other cutting.

I use the ruler. Have never used the lines on the mat to line up. Never had any problems.

This is how I do also.

I never used the lines on the mat till I watched Ricky Timms. He's so about making it fast and simple! If it's good enough for him, it's good enough for me.

But truthfully, I use my ruler more than the lines and along with the lines. Old habits...

My mat doesn't have lines on the side I use, and they're metric on the other side which only confuses me! I've only ever used my rulers.

I never use the mat for measuring.