Unfortunately, the same eyes that will "miss" a flaw during the piecing process, can also miss a flaw at the quilt shop. I think it's even more likely to miss at the Quilt Shop, IMHO. When I hit the Quilt Shop, I end up looking at bolt after bolt of fabric, hauling out my "matching/contrasting" patches, and so on. I don't go that often, so it's usually a big haul day. By the time I get to the cutting station, I've practically got a headache from looking at so many patterns. While I do check out the fabric while it's being cut, it's these tired, fabric-worn eyes doing the checking. I do my best. I have caught flaws. But let's be kind to ourselves as well, and recognize that we are not always in the best "space" to be checking for flaws while at the cutting table. Sometimes I'm rushed and pressured, sometimes I'm running late, sometimes I'm just tired because this is coming at the end of my errand list -- you name it. So don't beat yourselves up. Do your best with the flaws. If you find them when you get home, take the material back if you can. And if you can't, do your best to have fun with the flaw. I once had a long, black, obvious thread in a light blue fabric, and I "fussy cut" it so it looked like a streak of lighting across a 4" block, and everyone who sees it asks me how I managed to put that thread there like that! It's a striking element of design! As my Mother used to say: When life hands you lemons, made lemonade!