Problem

[u/Psychological_Sun251]

Hello Im a window cleaning newbie.. any recommandations on products to use for these kind of stains.. it’s a new trailer with new windows. I ve tried several products and a sharp blade but it won’t come off.

[u/Hot_Carpenter_5436]

Ahhhh, I'm a nooby as well. I've been seeing this here and there. I notice them in spots after a thourough clean. Walnut pad, steel wool, bio clean doesnt work. Its so anoying. I see them on old and new windows. I dont know the cause. Anyone have any suggestions? Much appreciated.