Discoloration from knitting needles?

Hi! I’m a newbie here, and I have a question! I knit a pair of socks recently on #1 Addi Pro needles and used cotton sock-weight yarn. I noticed a ridge of grayish discoloration along the one sock which hasn’t come out with regular washing.

My daughter is knitting on #000 needles and 100 % cotton crochet thread, and I’m noticing a similar thing happening with her project.

Does anyone know what this is, and how to prevent/remove it?

Thanks!

I’ve never had that happen. :??

I use addis and have never had that happen. Maybe add some Oxi-Clean to the wash. That works for everything for me :slight_smile: