It's etched if it's done right, Bob. But if its application is something like a stage or architectural lighting system, there's no need for it to be image-forming. Let's just say, I've never encountered the term "roughened" before with respect to AN glass. That could be clarified with a phone call; but it would seem a very clumsy way of trying to market something which we need to be quite specific. I have never personally encountered a sprayed product; I have seen some examples of less than ideal texture.
As we were part of Gepe we would visit the factories in Götene in Sweden, Garmish Partenkirchen in Germany as well as the Dutch factory.
Gepe, at their height, just in Sweden, used more then a mile of AN glass a day manufacturing 35mm and Super Slide mounts! The production was fully automatic and human hands only were involved in monitoring the production line equipment and piling master cartons onto Euro pallets. So we could not see the glass being position on the plastic mount before the metal mask was used to fasten it down.
But we did have long talks with the engineers, Marketing and Sales executives, all sons or nephews of the founder about types and choices for AN glass and why Gepe uses acid etched glass.
Their factory’s were always fascinating to see the production.
Unfortunately times and market conditions have centralized their production and all slide mounts today are produced today in Garmisch and the Swedish and Dutch factories have been sold.
But we did get a very through training about quality AN glass vs cheap AN glass.
Durst 138 ANR 5x7 Glass by Nokton48, on Flickr
Glenn says he is out of Anti Newton glass, but suggests perhaps coated glass? We will see.
Meanwhile I snagged this original Durst 138 5x7 ANR glass (German Ebay) for about $85 total delivered.
Since this is new very old stock, I would guess it is the acid etched good stuff?
Last edited by Daniel Unkefer; 14-Jul-2019 at 14:27.
Flikr Photos Here: https://www.flickr.com/photos/18134483@N04/
“The secret of getting ahead is getting started.”
― Mark Twain
Some years back I did extensive experiments with coated glass, mostly Tru Vue AR, obtained from a local high-end framing shop. It was effective in suppressing Newton's rings, but it was very difficult to find large pieces that didn't have flaws that could show up in a print if the glass was used in a negative carrier or contact printing frame. These flaws were irrelevant in framing use, so the shop couldn't get excited about them, and eventually I gave up as I concluded my search for really clean pieces was just causing aggravation all around.
Possibly it was a matter of how this shop stored and handled the glass. If you do explore coated glass, please do let us know what type, where you're getting it and how it works out for you.
Daniel - very good stuff.
Posted this before, but in my set up (Durst L1200 laborator with condensors) I saw the pattern of my original Durst AN glass back in my prints, not always though. So for formats upto 6*6 I now use glass on the bottom, and a glasless frame on top, and for 4*5 I use glass (original Durst) above and below, luckily I had no prblems with Newton rings, maybe because the humidty is mostly in the 60-75% range.
A trick I used in the past is to take a powdered examination glove (used the be the standard, now much rarer) and snap it in the vicinity of the opened film holder. A tiny bit of powder (Maize flour I seem to recall) landed on the glass, it did not show up in print, but did work in preventing Newton rings..
best,
Cor
Good to hear of a powder practitioner as described in a link in Post # 3 this thread.
However as Cor infers they may be very hard to find. FDA Banned 2017.
Tin Can
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