I've heard and seen this argument many times, and it's hardly a scientific or definitive test. Here's what usually happens: A framer frames up a cheap print (wouldn't want to ruin something expensive after all) and uses half regular clear glass with about 40% protection and half UV filtering glass with 97-99% protection. Then up it goes in the window. Within a matter of weeks both halves are faded. Conclusion: the crap don't work.alittle wrote:I thought I read a post here where someone conducted a study, using strips of different types of glass, and the UV protection essentially did nothing. Anyone know what I'm talking about?
Not quite. First, with the cheap print you get cheap paper and cheap ink. Neither are designed to last forever and the inks used are fugitive, to borrow a word from the conservation world. In other words, they're chemically unstable and exposure to light (any light) will cause them to degrade faster.
Second, they're asking the glass to do something it was never meant to do: protect from direct light exposure. Once you reach a certain light intensity, nothing will prevent fading, only slow it down a little bit.
Here's an analogy: TruVue used to have a tagline: It's like sunscreen for your art. It's quite apt. Now, I'm very fair-skinned, just like my mother was. I don't tan, I go from lily white to red with nothing in between. Now, if I go to the beach I can use sunscreen. Does that mean I can stay outside in the bright sun for eight hours and not burn? Hardly. It just buys me some time. It means that I can go out in the sun for maybe three hours and end up with the equivalent of one hour's exposure to sun.
Does this mean that UV protection is worthless? No. It's cheap insurance. Another analogy: Seat belts and air bags. They're not 100% effective 100% of the time, but I can guarantee you that if I don't wear them I would be a lot worse off in the event of a wreck.