Reversed Glass & Light Filtration

[Shayla]

A customer brought in her own frame for broken glass replacement. When our helper took out her piece of Museum glass, she noticed that it had been put in the frame backwards. I don't know how long ago it was framed, (somewhere else), but this has me wondering. If a piece of conservation glass is reversed, does it still protect the art as well?

 

[Greg Fremstad]

Please know or remember that you can filter out 100% of the 'harmful UV rays" but the art will still fade due to the rest of the visible light spectrum. I tested this myself back in the 70's with the first UF filtering Plex (UF3 I think) a covered an 11x14 easily fading photograph with strips of glass, regular plex, uncovered, and a strip of aluminum. I put it in the skylight (Northern California) and in 6 weeks you could see the difference . Every part under the various strips faded except under the aluminum. Don't tell your customers that UV glass will keep their art from fading. Read the claims made by the supplierS of UV filtering glass and acrylic carefully. Yes.. it does help but it's more important to explain to your customers to keep the good stuff out of bright even reflected light sources.

 

[Shayla]

Please know or remember that you can filter out 100% of the 'harmful UV rays" but the art will still fade due to the rest of the visible light spectrum. I tested this myself back in the 70's with the first UF filtering Plex (UF3 I think) a covered an 11x14 easily fading photograph with strips of glass, regular plex, uncovered, and a strip of aluminum. I put it in the skylight (Northern California) and in 6 weeks you could see the difference . Every part under the various strips faded except under the aluminum. Don't tell your customers that UV glass will keep their art from fading. Read the claims made by the supplierS of UV filtering glass and acrylic carefully. Yes.. it does help but it's more important to explain to your customers to keep the good stuff out of bright even reflected light sources.

Thanks for adding this. When designing, I tell customers about the UV filtering properties of the glass. Then, I say, 'Anything can fade, with time. Not just from that missing one percent, but from all the other light in the spectrum. Heat can also cause fading, as can the quality of the media.' With prints on paper, that often leads into a chat about the value of pigment-based media, over dye-based. I also encourage keeping it out of sunlight or fluorescent light.

So, I hear your about UV protection not guaranteeing a fade. At the same time, I've had plenty of pieces come in that were previously framed, and the worst fading was with regular glass.

 

[wpfay]

Back to your question.
Probably, or there wouldn't be that little instruction printed so cleverly in the margin about cutting the opposite side, and having the printed side face the art.
Both TruVue and ArtGlass have those instructions on their 99% UV filtering products, so I don't think they are just messing with you. Besides, have you even made the mistake of ignoring those instructions? I have. it wasn't pretty. Ruined a carbide glass wheel and a sheet of MG. I was a tad impatient.
Exactly why the coated side should face the artwork, other than it is a little more prone to scratching, I don't know.

 

[framah]

It's purely for protecting the coating from scratching. A filter is a filter, no matter how the light goes thru.

Like.. if you put in backwards, it sucks the light into the art???

 

[alacrity8]

It's purely for protecting the coating from scratching. A filter is a filter, no matter how the light goes thru.

Like.. if you put in backwards, it sucks the light into the art???

Exactly.
For protection of the art purposes, it does not matter where the coating is.
For protection of the film, it does.

More than a decade ago, Tru Vue decided that it would be more cost effective to put the UV and Frosted coatings on the same side of Conservation Reflection Control.
This gave the same UV protection.
It was also the cause of a bunch of damaged glass, so they switch the coatings back to opposite sides.

 

[monkframe]

Thanks for adding this. When designing, I tell customers about the UV filtering properties of the glass. Then, I say, 'Anything can fade, with time. Not just from that missing one percent, but from all the other light in the spectrum. Heat can also cause fading, as can the quality of the media.' With prints on paper, that often leads into a chat about the value of pigment-based media, over dye-based. I also encourage keeping it out of sunlight or fluorescent light.

So, I hear your about UV protection not guaranteeing a fade. At the same time, I've had plenty of pieces come in that were previously framed, and the worst fading was with regular glass.

+1
I always give the lecture you mention, about how the light destroys everything. And I tell people that UV-filtering glazing merely slows down the inevitable if the work is in direct light.

I had a fellow in w/a concert poster that was sort of gauzy pink in hue. I made him to understand that this work needed to be in the darkest place in his house!

 

[Rick Granick]

As mentioned, never make any absolute claims as to fading. I always explain that all light causes fading due to its energy, but that we need the light to see the work.I usually say that the UV filtering helps slow the process as best we know how, but that placement of the art is important as well. The best description is that it helps keep the art looking as best possible for as long as possible.

As to the original question, cutting the side opposite the printing is to prevent scratching the coating, to get an effective score, and to prolong the life of the cutting wheel.
Rick

 

[Shayla]

As to the original question, cutting the side opposite the printing is to prevent scratching the coating, to get an effective score, and to prolong the life of the cutting wheel.
Rick

This is what I'm hoping, that it's just to protect the finish. And that the protective qualities work both ways.

 

[Rick Granick]

I think you can sleep soundly without concern about that.
Rick

 

[Artglass by Groglass]

If we're not too late to the party, we'd like to comment here – the UV block will work the same, even if the glass has been installed backwards. However, the UV-coated side is a bit easier to scratch, which is why we always recommend framing with the UV-coated side facing inwards. If the coating gets damaged, it may also reduce the UV-filtering qualities of the product.

You can find out more at https://artglass.groglass.com/ or contact us directly if you have any specific inquiries about our products!