I've had a few pieces were the knots were not bleached on my #4-#6 brown hair pieces. I just bleach them on my own.. but sometimes it's not very successful, and I still have a bit of a grid pattern going on. It's usually pretty darn good at the hairline however. My current stock piece has the front contour bleached so well that there is a yellowish contour pattern were the factory bleached the knots. I tried bleaching the rest 2-3 x and got them pretty decent.. but still not that great. The best thing to do is to learn how to do this stuff on your own.. If you can afford it, get 3-4 pieces at a time b/c they usually take close to 2 months to get custom pieces.