Glazing is often the last decision you make when you are completing your framing package. And the options—much like the rest of the framing process—are manifold. Framing and conservation experts often recommend acrylic, which offers both UV protection and anti-reflective coatings; however, acrylic is prone to scratching, builds up static charges, and, to some framing purists, is inferior to traditional glass. Standard clear glass is the most common type of framing glass, but it often casts a green tint due to its iron content. UV-filter glass, though protective, can cast a yellow tint.
Compounding the complexity is the fact that Groglass, a manufacturer of high-performing coatings for glass and acrylic, has developed a collection of glass that offers the same, if not better, protection and clarity than any other protective glazing option—and all without any optical distortion or color variations.
Glass, acrylic, UV filters, anti-reflective coatings, green and yellow tints, iron contents, distortion…it’s a lot to take in when all you’re trying to do is put the finishing touch on your frame. Knowing what different types of Artglass we offer is all well and good, but it’s a lot more helpful if you know what’s behind the mumbo-jumbo.
How Light Damages Photographs
When we say “light damages photographs,” it is a somewhat incomplete or incorrect phrase. Light, which is electromagnetic radiation, refers just to the part of the electromagnetic spectrum that we can see. This light does damage photos, but the bigger culprits are ultraviolet and infrared radiation.
When light hits a photograph, the energy is absorbed by the molecules within it. This energy causes the molecules to go through chemical reactions—what those reactions are depend on a variety of factors. Different types of radiation, including visible light, UV, and IR, cause different types of reactions.
- UV radiation is the most damaging as it hits the photograph with large amounts of energy in a short period of time. It causes yellowing, embrittlement, and overall disintegration.
- IR radiation heats the surface of photographs and causes cracking, lifting, and color changes.
- Visible light, though essential to actually see the photographs, isn’t free from blame. It, too, causes fading or yellowing.
The UV Protection
As is obvious, protecting photographs from UV light is imperative—that is, if you want your photographs to last for longer than a couple years. There are different ways to filter UV light in framing glass. TruVue, for example, uses a silica-based UV blocking coating with a matte finish that blocks UV light.
Groglass’s Artglass employs UV-blocking, multilayer molecular films—equal to 1/400th of a human hair—to provide UV protection. Artglass UV WW and Artglass Preservation Clear both offer preservation-grade UV protection of over 90%, which is calculated as an average UV-light blocking capability in the 280-380 nm spectral region (i.e. the measurement of the wavelength under which UV light falls, including both UVA and UVB). The difference between the two is that Preservation Clear has a reflection of about 8%, while UV WW has no reflection due to its antireflective coating.
Glass reflects light. It can be very irritating to have beautiful artwork in your home, but never be able to see it properly due to the glare that is inherent in glass frame glazing—this is why some opt for acrylic.
However, Groglass and some other glass manufacturers have developed antireflective (AR) optical coatings that reduce reflections and, ultimately, allow for an unhindered view of the artwork. Groglass uses a magnetron vacuum sputtering process (a method of applying very thin films—think on a molecular level!) that deposits the antireflective metal oxide coating as a molecular film that is less than a micron thick.
It’s so advanced it was originally developed for aerospace applications. This coating is applied to either one or both sides of the glass, and reduces residual reflections to less than 1% and increases the light transmission to 98%—meaning more light is transmitted to allow for a clearer image.
With Artglass, you don’t have to choose between UV protection and antireflection; you can have the best of both worlds. Artglass UV WW (where the “WW” refers to Water White glass, meaning it is made of iron-free silica) has both antireflective and UV blocking properties, meaning your photos are protected—and you’ll be able to see them with little to no glare!
See Your Photos Clearly
If you prefer glass over acrylic, then using Artglass offers significant benefits: namely, your artwork won’t suffer a quick fading death from harsh UV light, and you’ll be able to view them without the frustrating effect of reflection. But knowing the science behind why light does what it does makes it easier to choose the right glazing for your artwork.