This is sort of an aside -- but I wash the fabric before I cut.
And yes, I do wash - sometimes. It depends on where the fabric is from. I have many allergies in the family and sometimes I wash just to be sure. At one time, there was a line of fabric and all the dark colors had a mild fishy odor. You only noticed it when you were in a tight spot with a lot of it, but I I figured that needed washing. I find fabric purchased at Joanne's sometimes shrinks and sometimes not, so I do wash that. Some fabric has a lot of sizing and that too, needs washing.