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.
Last edited by GailG; 01-16-2012 at 05:46 AM.