I know that the thread you use does make a difference. I was having problems with a standard 1/4 seam but started using Aurofil (sp?) and it did make the right size blocks. However, I have lots of thread I want to use and so since it's bigger I now use a scant 1/4 and it works great. My Viking has a 1/4 inch setting, guess what- it's a scant 1/4. Guess 15 years ago Viking decided it made a difference. Wow.