Fiberglass can be had in the thinner gauges so that it is less visible. Aluminum with oxidize and is usually not a good option.

The stuff that you hear of as "Invisible" is usually a very thin wire stainless that was, for the longest time, proprietary to the different larger window companies and probably not something your local screen company is going to have.

Home Depot has a thinner fiberglass mesh.

buy a roll and tack it up.

Toward the bottom of this is the info about screens; https://www.oldhouseguy.com/wood-storm-windows/

Thanks for all of the info. How does the durability and wear of ultra thin stainless compare with thin fiberglass?

Windows on Washington - I found this Ultra View screen by Pfifer on Home Depot website. Do you think this is comparable to the formerly proprietary "invisible" screen material you mentioned?

That appears to be a thin gauge fiberglass mesh. While they do a nice job and are quite durable (under normal use), the thin wire stainless should be a bit more robust and can typically be run at smaller thicknesses which does make it appear nearly transparent.

Copper will last for 65 years, but is cost-prohibitive.

Will copper not turn a green patina? I wouldn't worry about the upfront cost as much as someone stealing them!

Yes, eventually it turns a weathered bronze color. I have only been asked to do copper screens twice in 32 years. $$

Sombreuil, How did they look when they were done? Do you know if they held up well?

I don't know if they are worth the money or not, I just want something that looks nicer than typical fiberglass.

They will weather unevenly to begin with, but eventually the streakiness goes away and the color evens out. The material is very strong, but of course it can be creased, like all other metal screen.