I just returned from the framing shop to price glass. These are the prices for 4X5, each…regular glass, $3.25, non-glare, $8.25, UV, $13.00, and Museum glass, $32.50. I guess the museum glass is the stuff to use, even if it is expensive. But I’ll be shopping around to see if I can get it a little(lot!) cheaper.
I have been using museum glass for a while but I’m growing to dislike it. The anti-glare coating is great if you’re framing a print but it doesn’t do much when you’re properly viewing a daguerreotype. Since you have to view them at the proper angle anyway I think that it’s kind of a waste. Furthermore I find that the coatings actually tint the image in a way I dislike.
Regular glass has a green tint to it – easiest to see when you look at the edge. This is because of the iron oxides in the glass, you can get low iron glass – its not very environmentally friendly – they use arsenic in the production process to get rid of the iron oxides. One of the commerical names for the high spec version of this glass is called borafloat, waterwhite is another one. A dag behind white glass does look a lot nicer and there are conservation advantages too – the high spec glasses are less prone to weeping – when the silicates leach out of the glass over long periods of time. Another advantage for me is that when painting a white passe partout I don’t have to color balance the white to pink so that when reverse painted onto the coverglass it appears as white should do, i.e. no green tint.