Artglass Clarification
Dear Grumblers,
First off the disclosure - I am connected to GroGlass (the producer of Artglass), just as Jim is connected to TruVue, so I do have a bias for their products. However, I am primarily guided by the quest for intellectual honesty when addressing these questions. In response to your posts, a few corrections:
“Baked Right In” – the Artglass and Artglass UV coatings are not “baked”, but they are magnetron sputtered, just like TruVue’s Anti-Reflective layers. The UV filtering is achieved by adding more sputtered interference layers, and the UV is reflected, while TruVue uses an additional chemical deposition process (the orange-peel) to roll on the UV-absorbing layer.
“Artglass is Clearer” – what the Omega salesperson was trying to show is the difference in visible light absorption. By placing the Museum Glass on a piece of white paper or mat, you will see that the glass turns the white into a color of rust. This is because it is impossible to get a sharp 99% cut at the UV/Visible boundary without affecting the visible light transmission. Artglass UV cut stops at 92% precisely for that reason – not to affect the visible light transmission and stay true to it’s promise of “100% Art”.
“97% is the cut-off for Conservation Framing” – Just as it is important that we disclose our affiliations, it is also important to say that both FACTS and Image Permanence Institute have one corporate sponsor from the glass industry (TruVue), and their recommendations match exactly the TV product specifications. Would you take nutrition advice from the Big Mac Institute? It is not their fault, of course – for a long time TV had been the only game in town, so what use is there to create standards, which are not achievable…
I will be the first one to advocate UV protection for framed art, but it has to be looked at holistically. None of the abovementioned “authorities” is speaking about the damage to the artwork by the visible light as it is not in the interest of the framing industry, but the ugly truth is - if you want to really preserve something, don’t display it and keep it in a climate-controlled dark closet! I highly recommend this article:
http://en.wikipedia.org/wiki/Picture_framing_glass - a balanced, well-written review of the glass choices and the UV issue.
Looking for intellectual honesty, not only marketing opinions…
BF
PS Bob - Schott AG is the same company that made the first “shot” glass, so it is not a cute play on their name – it IS their name (
http://en.wikipedia.org/wiki/Shot_glass#Friedrich_Otto_Schott.2C_Ernst_Abbe_and_Carl_Zeiss)
PPS Jim – Claryl does not block 78% of UV. It does not transmit any less UV than uncoated glass. However, the fact that it lets in around 6-7% more light in all spectra, and since the visible light also damages artwork, it is more damaging to an artwork to display it behind Claryl than behind regular uncoated float. As I recall, regular clear float blocks around 40% of UV between 300 and 380.