Low reflective glass + platinum prints

[Jean Fergus]

I purchased 6 platinum prints from an artist last year. I had them framed at John Rogers in London and specified I wanted low reflective, non-UV coated glass. The pictures were returned and when view the glass casts a bright green reflection making it impossible to view the prints. John Rogers assures me that all low reflective galss casts this hue and that the only alternative is regular glass. I have done some research and find that low reflective comes uncoated or UV coated. Is my glass UV coated? If not, why it is reflecting green?

Thank you for your help.

Jean

[Robert A. Zeichner]

All optically coated glass surfaces have a color tinge to their reflections. Which color relates to the thickness of the coating, which in turn is determined by the glass type being coated. If you look at photographic lenses of various types, you will observe green, turquiose, amber, magenta tinges depending on when and by whom the lens was made. In the case of multicoated optics, a lens can reflect a number of different color tinges.

The brightness of the reflection is a relative thing and I believe if you were to compare non-coated glass with the stuff you purchased, while it's reflections would be "colorless" (actually just the colors of the objects in the reflection) those reflections would be much brighter and more noticeable than the reflections from the coated glass. That said, it is possible that the batch of glass that you purchased might have been mis-coated. Coating glass is not exactly an easy thing to accomplish and I suppose it is possible that the thickness that was deposited was incorrect. I've been using Tru-Vu AR glass for those clients of mine that need to hang photographs in rooms with difficult lighting, such as in ones with window walls. It has performed very well in those situations with clients claiming that the prints "pop" right out of thier frames. AR does have a greenish tinge to the reflections, but I wouldn't say it was bright.

I'd be very curious to hear what else you might discover about this problem.

[David F. Stein]

The anti-glare and other coatings now put on plastic eyeglass lenses are similar. If you have such a pair, you will notice the "tinges" you and Bob speak about. You might try "non-special-anything" Plexiglass®. Our Light Impressions company likely has some good info on these issues on its web site. There is a movement, I believe, in painting to just mount uncovered paintings-SO WE CAN SEE THEM. A frame is a necessary evil and often an enhancement to art but it mever made sense to me to work so hard to create a photograph and then cover it up. GOOD LUCK.

[Jim Noel]

I am a platinum/palladium printer, as well as other vintage analog processes. I long ago decided that the only way to look at a good print is to look at it, and nothing else. In other words, I no longer put glass, plexiglass or any thing else in the frame to hide the images. My belief is that a well processed print, particularly a platinum or palladium, is permanent enough to sustain itself without additional covering. I have had no problem with people wanting to touch the images, but they do marvel at how much more they can see. JIm

[Darin Cozine]

Rather than requesting a coated glass, you may also want to ask for a better quality glass. Regular plate glass has a green tinge to it. There are other types of high-quality glass that have a better transmission of light yet are not coated.

Darin

www.cozinephoto.com

[Robert A. Zeichner]

Just to clarify (no pun intended) a point, AR glass shouldn't be confused with "non-glare" glass. AR is optically coated like a photographic lens and is perfectly shiny clear glass that does nothing to diminish the appearance of the sharpness of a photograph. Non-glare glass typically has a texture that scatters light and gives the impression of reducing glare, but at the same time, softens the appearance of the image behind.

[clay harmon]

Water white Denglas is the only way to go if you really want to see your prints without a color cast. It is expensive, but amazingly effective stuff. www.denglass.com I use it on all my framed prints on my home gallery wall. When I sell prints through my local gallery, I give the purchaser the option of denglass for an extra $25. Most people will willingly pay the extra $$ when they see a side-by-side comparison.

[Jim Becia]

There is a non coated anti-reflective glass out there called Image Perfect manufactured by Zuell Corp. Does avery nice job of maintaining sharpness and color fidelity. I have been using it in my frame shop for about 10 years. Jim

[Chris Gittins]

Standard anti-reflection coatings reduce the reflectivity to less 0.5% average over the visible. (For example, see http://www.escoproducts.com/3techcoatbbar.html.) If you can detect 0.5% back reflection, you have better eyesight than probably 99.99% of the population. In all seriousness, there is no perceivable back reflection or coloration from broadband AR-coated glass. (I use AR-coated optics at work on a daily basis.) The green hue you describe is characteristic of coatings which are a) only anti-reflective over a narrow range of wavelengths, or b) viewed at a high angle of incidence. It sounds to me that they didn't give you what you asked for.

Chris

[Richard Laugharn]

Some suggestions from another framer:

Some sort of glazing is important beacuse of the objects vulnerability to abrasion, contamination etc. Lamination seems inappropriate for platinums (to say the least), but may offer a low cost solution for management of reflections for other media, though I would have archival concerns. We use acrylic when the weight/fragility of glass is a liability, or when glass is not available large enough for the application. However, acrylic (i.e. Plexiglas) creates more distracting reflections than other glazing options (not least because it does not lie as flat). Of course, the scale of the vast majority of platinum prints does not dictate the use of acrylic. So glass is most likely the solution...

I'm sure I'm not alone in finding the matte surface and shadow detail to be two of the most beautiful attributes of the platinum process. These are precisely the two areas most compromised by "regular" glass. If we are to display these objects, optically coated glass is the best solution in most cases to preserve for the viewer these subtle but essential qualities.

Another fork in the road is whether the glazing should filter UV light or not. Platinums are much less vulnerable to damage from UV light than other photographic processes, so I would feel comfortable suggesting a non UV glazing option if the artwork was to be displayed in areas that were relatively low in UV (i.e. interiors w/o direct or nearly direct sunlight and/or flourescents). UV coatings are available for optically coated glasses. They cost somewhat more and, and though the coating is clear, they can have a slight "ripple." This goes to Jean's original question: does the glass in question have a UV filter? The UV coatings are distinct from the optical coatings. What Jean describes does seem to be optically coated (though, like Robert, I'm puzzled by the word "bright"). If there is a slight clear ripple to the glass (you'll have to look closely), it has a UV coating; if not, it probably doesn't. I would also offer this advice: trust your framer. They are trying to provide the best solution, and while mistakes happen, I would be inclined to think you got what you asked for. I do find that the UV coating's ripple, while subtle, can be a bit distracting in some cases. Without a doubt, a non UV optically coated glass (i.e. what Jean asked for) offers the viewer the best experience possible.

It is also worth mentioning that reflections are strongly determined by the environment the art will be displayed in, and we can often drastically reduce reflections by moving the artwork or manipulating the light around the artwork.

Richard