UV blocking Acrylic for framing question

[Pic One]

While I understand there's at the very least a negation of an OBA-content paper's brightness using a UV blocking acrylic, and at worst there can evidently be a detrimental effect (color shift?), my question is whether reversing the UV acrylic would remove the issue?

The reason for asking is twofold:

1.  In the past, UV acrylic I received was clearly labelled (on the peel-off film) to ensure that a specific side is facing out (ie. I suppose this side containing the blocking layer?).  Having the sheet facing the 'wrong' way would imply that you don't reap any UV blocking advantage.   However, I haven't recently received any Acrylic labelled this way, so wonder if there are brand differences in how the UV blocking is built into or onto the substrate?

2.  Going this route would mean I could buy UV Acrylic in bulk (without knowing future intent of the material) and could theoretically use facing one way or the other for a given print on a given paper type.

If this does work..  is there any easy way to test to find out which side blocks incoming UV light?

3.  I reserve the right to freely admit that none of the above makes any sense at all, and I'm completely clueless. 

[DeanChriss]

My understanding (based on Tru-Vue products) is that UV blocking glass has a filter layer that's kept toward the artwork so it's not damaged in handling, cleaning, and the like. UV blocking acrylic has the UV protection integrated into the acrylic itself, and it's not a coating. In either case I can't imagine how reversing the filter would allow UV through the product.

[Pic One]

No idea if it works facing only one way and not the other.  I guess in similar way mirrored sunglasses don't look mirrored if you're wearing them?   If the UV protection is invisible to the naked eye, I don't know what or how it works.

[hugowolf]

Unlike anti-reflective glass, I have never seen any color shift with UV cut acylic.

Brian A

[mstevensphoto]

Unlike anti-reflective glass, I have never seen any color shift with UV cut acylic.

Brian A

same here. I actually really dislike anti reflective glass in most instances. I see the "haze"

[DeanChriss]

"Anti-reflective" is not the same as "UV blocking". They are completely different things.

There are different types of anti-reflection coatings. Some, like "museum glass", are like the anti-reflective coatings on a camera lens. Those are completely invisible and don't shift colors. Others use a find texture on the glass. They can look hazy, and the haziness increases with the distance from the artwork. That's why the manufacturers recommend just a single thickness of mat between glass and artwork.

[framah]

Dean has it right.. There is NO difference which way the piece is installed. The UV protection will still work. End of that part of the story. Period.

As for the UV acrylic having a sticker on it telling you that side faces out.. that makes no sense as per the above and I see no reason for that sticker to be on  there nor have I ever in all of my 2 decades of framing seen a sticker like that on acrylic unless it was more than just a UV filtering acrylic but also had a non-scratch coating which WOULD require that side to be facing out.

As for this statement you made:

While I understand there's at the very least a negation of an OBA-content paper's brightness using a UV blocking acrylic, and at worst there can evidently be a detrimental effect (color shift?), my question is whether reversing the UV acrylic would remove the issue?


How do you figure the UV filtering will negate the papers brightness or create a color shift?   I feel you are working from a bucket load of mis-information about what UV filtering does. The only color shifting from UV or UV filtering is that those wavelengths will cause fading and UV filters in glass and acrylic filter out the most harmful wavelengths to minimize the fading.  Even plain glass still filters out about 60% of harmful wavelengths.

Not to get on your case here because I really am interested in the source, but where did you get that information?

[bill t.]

the anti-reflective coatings...Those are completely invisible and don't shift colors.

Until you get fingerprints-in-space from somebody poking it to see if there's glass there.

And since we're discussing UV protection at the rooky level here, I think it's important to note that UV glazing is only a degree of improvement over no UV protection, but it should never be mistaken for an excuse to display art in extremely bright conditions under any sort of light source.  UV protection only slows down fading due to light energy, it does not completely prevent it.  And of course there are things besides light that can also cause fading, heat and humidity being examples that greatly affect inkjet prints.  If you want your prints to endure the ages, UV protection is just one of many considerations.

[Wayne Fox]

How do you figure the UV filtering will negate the papers brightness

Maybe he was referring to brightness with OBA papers?  Using UV absorbing glass over OBA papers can negate the effect of the OBA’s.

[Pic One]

Dean has it right.. There is NO difference which way the piece is installed. The UV protection will still work. End of that part of the story. Period.

As for the UV acrylic having a sticker on it telling you that side faces out.. that makes no sense as per the above and I see no reason for that sticker to be on  there nor have I ever in all of my 2 decades of framing seen a sticker like that on acrylic unless it was more than just a UV filtering acrylic but also had a non-scratch coating which WOULD require that side to be facing out.

You may have hit on what I'm recalling.. it was a couple years ago.  Are there perhaps (cheap?) Acrylic sheets that use a coating layer instead of impregnating the substrate?   I've been using Acrylite OP3 typically, and from what I've read, yes, I seem to have no issues about which direction I face the 'glass'.

As for this statement you made:

While I understand there's at the very least a negation of an OBA-content paper's brightness using a UV blocking acrylic, and at worst there can evidently be a detrimental effect (color shift?), my question is whether reversing the UV acrylic would remove the issue?


How do you figure the UV filtering will negate the papers brightness or create a color shift?   I feel you are working from a bucket load of mis-information about what UV filtering does. The only color shifting from UV or UV filtering is that those wavelengths will cause fading and UV filters in glass and acrylic filter out the most harmful wavelengths to minimize the fading.  Even plain glass still filters out about 60% of harmful wavelengths.

A couple links, from which maybe I admittedly drew the wrong conclusions.  But the gist is idea that paper profiling is done with the assumption that UV light will activate the OBAs.  Blocking the UV effectively diminishes the accuracy of the color profile as the paper white is affected?  ie.. from the first link, the suggestion is that non-OBA papers have more color constancy.  The inverse would be that OBA papers do not, and this is more accentuated by the effects of blocking UV rays that the paper profile might be based on receiving?
http://www.dpreview.com/forums/post/38165814

A second link, from post from Ernst Dinkla, includes below snippet.  Does a change in a paper's whiteness change the color response?
"Framing them behind normal glass already reduces the fluorescence effect and shifts the paper white, that effect increases with any measures taken to block UV light for enhanced longevity; UV cut glass in the frames and lighting without UV content."

http://www.dpreview.com/forums/post/54045418


Not to get on your case here because I really am interested in the source, but where did you get that information?

[Pic One]

Maybe he was referring to brightness with OBA papers?  Using UV absorbing glass over OBA papers can negate the effect of the OBA’s.

Yes, I was referring to the change of the paper's white using UV blocking glass over OBA-containing paper.  I would think changing a paper's whiteness would shift the color by changing the relationship of different colors to one another.  Certainly it seems this would throw off the profile and or the softproofing view.

  The original, though evidently flawed, premise was to use uv acrylic facing one way to block uv when framing with non-OBA paper; and, when you do frame with OBA-containing paper, use the acrylic facing the other way so that UV light would not be blocked.   

I don't know whether this would work with UV glass, since apparently glass has the uv blocking built into an applied layer that sits on the glass, it's not clear whether its blocking characteristic only works facing one way or the other, or is bidirectional.

[framah]

Thanks for offering me those bits of info about the OBA's.

Seriously tho.. there will be no difference in the UV properties of either glass or acrylic  no matter which way you put it in front of the print.
and no, there is no acrylic that has the uv layer added on. It is IN the acrylic. (I think it is magic! Something we muggles aren't privy to.)

[elolaugesen]

Anti reflective glass colour shift - please tell me more???

Use it a lot for original art?   Colour shift?

Any glass changes colours.  Ie colour shift....   Some less than others..   Worst is non glare glass.   

Tru vue anti glare quite good....  (Especially considering reasonable price compared to best museum....)

In the end ...   It depends where you hang it with the light all around...at home, office, gallery. Etc..  The same art work will look different in every environment......    And then there is the person looking at it.. With or without eye glasses...

[bill t.]

Here's an idea!  Buy a piece of anti reflective glass from a framer, he may make you a deal on scrap.  Have him throw in a scrap of ordinary glazing, maybe Acrylite-FF.  Make an OBA print, and a non OBA print.  Walk those materials around the interiors of various houses, offices, galleries, and other venues where wall art is used or sold.  Make notes.

I tried all those combinations over the years, though not in a systematic way.  But I don't recall my old OBA-rich Enhanced Matte images suddenly dropping dead from being place behind any sort of glazing, and I tried them all at different times.  In general, the differences never seemed noticeable enough to override the logistical imperative of using what was on hand at the time.  As for those seeking color shifts, ordinary float glass from the hardware store lends an attractive green bias to your forest imagery and is also suitable for portraits of people you don't like.

[Wayne Fox]

I tried all those combinations over the years, though not in a systematic way.  But I don't recall my old OBA-rich Enhanced Matte images suddenly dropping dead from being place behind any sort of glazing,

I agree, using an OBA paper behind UV glass doesn't really ruin the image.  The only way you tell it's doing anything is to compare to the same print behind non UV glass.

And the "color" shift referred to may be related the color shift of reflections in the glass, not in the colors of the print itself.  If you look at a reflected light source from the surface of museum or artglass, not only is is substantially less bright and less noticeable, the color of the light source takes on a strong blueish or greenish cast.  However, that shift doesn't seem to have any effect on the colors in the print itself.