How awful. Hancocks should replace your fabric.

I never use my mat to measure. only straighten an edge . cmaras

Good to know your sanity is no longer in question. :o

Good to know your sanity is no longer in question. lol.

Good that you figured it out.

This whole discussion about using cutting mats to measure probably explains why I never participate in BOMs. It has been my experience that if I recieve blocks from other quilters there are always several that are not the same size. It usually happens with pieced ones. It makes assembling them into a quilt, if even possible, very frustrating. My husband is a machinist who works with metal everyday. He says in order to be truly accurate with it you have to control things like temperture as metal contracts and expands. We all know that fabric stretches etc. After more than 40 years in quilting I know why I prefer wholecloth quilting above all others.

Chinese junk today, everything. My Fiskers matt is at least ten years old and really quite accurate. However, I sew garments and do home dec mostly. Any quilting is very basic so really don't need the exactness you have to have in delicate block building. Good luck in finding what you need for measurments.

As everyone says, do not use the cutting mat to measure. Use your ruler and the same brand of ruler for the whole quilt.

I haven't read the whole thread but I think the crux of the matter is that we use the SAME measuring instrument for everything we do on one project. If you cut by measuring on the mat, then use the mat to size up and square up the piece. Same with the ruler. Use the same ruler with everything you do on one piece. There are so many variables (such as the thickness of the lines printed). I hope I haven't repeated the same views as others that have been posted, but perhaps a good reminder can't hurt. Happy quilting.

Edit: Went back and read a few posts and was reminded that the amount of heat and steam used when pressing will cause the size of the pieces/blocks to vary.

You sure would never think to check a brand new cutting board. That's horrible. Probably made in China or somewhere and no checking at all. It gets frustrating.