Advisory:
I "treat" all my fabrics before cutting them using "the soak in hot water for hours, then wash and dry gently" for all the reasons that people do this - shrinkage, dye issues, chemical/dirt removal.
"Permanent Press" fabrics do have a memory that will trump the usual behavior of that fabric.
If a piece of fabric is stretched on the bias - when it is washed and dried - it will usually try to revert to having the threads perpendicular to each other.
If a block/unit is just a tiny/scant bit undersized, I will compensate by adjusting the seam allowances - not by trying to stretch the smaller piece. The reason, again, is that usually fabric will revert back to the size it was before being stretched.*
I have been able to stretch fabric a lot by soaking it in starch/sizing and then ironing it while it was soaking wet by the "rolling out pie-crust method" I do not advise it - because I was aiming for a 5.5 inch size unit and I think I got it stretched to about 6 inches. That unit ended up in the "that was interesting" pile.
*"Easing" a piece is another topic.
Last edited by bearisgray; 11-17-2020 at 06:00 AM.