Hi everyone - I have an issue with IA Ultra pretreat turning my heather grey shirts yellow/brown in the sun.
I've tried Gildan 2000, Gildan hammer, and FoL Premium ringspun...all the same. I've tried varying amounts of pre-treat, and there's no difference. It washes out a little, but not completely.
Any tips, or suggestions on what shirts to use instead. I'd really like to stick with heather if poss.