FACTS / PPFA and UV glazing ?

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realhotglass

realhotglass

MGF, Master Grumble Framer
Joined
Feb 20, 2003
Posts
662
Loc
Adelaide - South Australia
Hey all,
Sorry in advance for the long-ish post.

I refer back to this thread re FACTS . . . went into UV glazing.
http://www.thegrumble.com/showthread.php?t=45821

And sorry Jim, I think I missed your post below, but this encompasses the gist on my inquiry today. See your quoted below . . .

Jim Miller said:
Actually, the FACTS glazing standard called for 50% UV blocking in the frequency range of 300 to 400 nanometers. I'm not sure it was right when it was written.

UV blocking specifications would be difficult to compare when they include different ranges of light frequency. The only glazing specifications I've studied are from Tru-Vue. Their UV-blocking tests are in the frequency range
of 300 to 380 nanometers. They and PPFA call for 98% blocking in that frequency range.

Since (for "conservation" glazing) there is a very steep curve of light transmission from almost zero to almost 100% between 380 and 400 nm, most of the UV light between 380 and 400 nanometers probably would be transmitted and not blocked. So averaging for that 20 nm wider frequency range, from 300 to 400 nm, would drag down the average percentage of UV blocking.

I'm not sure, but maybe an average of 70% UV blocking in the range of 300 to 400 nanometers would be roughly the same as an average of 98% in the range of 300 to 380 nanometers.

Maybe RealHotGlass can set us straight on this.
Click to expand...

Ok, I have read here (I'm almost sure) on the G that some industry body of significance sets minimum 97% UV block for conservation glazing, but all I can find is this on the FACTS site, stating min 70% . . .
http://www.artfacts.org/standards/glz_2001.html
Section 6.00

I am currently trying to convince Schott to look at increasing their UV block on at least one of their Mirogard products (besides Protect, their premium, very costly, laminated).
Say on Mirogard Plus (currently 84%) to 98% or 99%.

Maybe it was the PPFA only that had the higher level recommendation for protection ?

If anyone can refer some links to this or other info, that would be great.
Would like to let them see some industry leading recommendations for higher level blocking.

If FACTS are indeed stating (only) at least 70%, and PPFA and TruVue are at minimum 97%, then maybe I only have PPFA to refer them to.
(TruVue obviously have a vested interest in the higher figures.)

Schott are hesitant to consider such a change for the very small Aus market, but I have mentioned to them several times that the US market almost demands 97% or better to be considered conservation standard.

Apparently, there is no such push from the European markets for higher than Schotts 84%, but from my observations the UK framers are getting very aware of UV protection, and they generally get pushed into higher levels.

I am just wondering now what is right . . . maybe it's just TV pushing the higher level, and the PPFA picking this up from there.
I mean, why wouldn't TV state that 97% + protection is needed knowing that you have the only viable option cost wise and with the distribution in that range ?

Oh, Jim.
I think you are right re the % avg . . . most refer to 380nm as their upper threshold of protection, even there the colour shift is starting to have an effect.
My coating is 95% in the 280 - 380nm range, maybe I should have it tested to 300 - 380 sometime and see what the difference is.
It is clearer on white paper than both TV and the old Guardian UV (ArtGuard).

Look forward to some links, and who knows, there might be some more meaningful competition some day in optical coatings ?

Regards,
Les
 
Les, the FACTS #GLZ2001 Standard for Preservation Glazing Materials is dated 2001, but it was actually developed and adopted in 2000, a full decade ago. Back then, there were few agencies making recommendations, and FACTS did the best they could to verify the benefits. I was a volunteer member of the research committee, and as I recall, the best we could verify was 70% blocking in the range of 300 to 400 nm. As noted previously, that may turn out to be be very close to the 97% recommended today in the range of 300 to 380 nm.

The Image Permanence Institute seems to be the most-credible, independent preservation authority these days. I have heard their recommendations are recognized and respected by CCI, AIC, PPFA, and some agencies of the U.S. Federal Government. Here is a very useful site for documentation provided as free downloads from the IPI:
http://www.imagepermanenceinstitute.org/shtml_sub/downloads.asp

And here is a link to their recommendations for preservation framing. The third line on page 7 recommends at least 97% UV blocking for preservation framing:
http://www.imagepermanenceinstitute.org/shtml_sub/preservationframing.pdf
 
Thanks Jim.

Found 'ISO 18902 recommends glazing that blocks at least 97% of UV energy.' in that pdf link, and that would be a good start to refer the Schott Glass people to.

I was expecting a little more input from others that know where to find PPFA data (if any).
Too often I see people wanting (credible) options to a single supplier in this market, and one response ?

I'm sure PPFA would have something somewhere in their vast resources that specifies a % recommendation, and this would be a credible back up to the IPI source.

This is the Australian head of sales at Schott Glass I'm discussing this with.
Hopefully he can send any relevant info back to their German head office and ask them to consider a better level of UV protection.
They may actually do some more research into the US and other markets and realise that better protection is something framers want and worthy of consideration.

Oh, and I feel FACTS should update their info.
How many other framing components / methods are as out of date ?

Regards,
Les
 
Sorry Les, Jim was on the task force that wrote the guidelines, so I figured his answer was what you were looking for.

I think I've read it other places, but ...

PPFA Guidelines for Framing Works of Art on Paper Page 43 recommends

"An acrylic or glass product that has a minimum 98 percent ultraviolet filter in the 300-380nm range."

Is that what you were looking for?
 
I understod that you are looking for credible authorities on UV blocking standards, and IPI is probably the most credible of them.

Tru Vue's recommendations are based on their testing and research over the evolution of their product lines. I'm not sure Schott would be impressed, except that Tru vue dominates in the USA market.

I have not checked, but you might also find recommendations on U.S. Government sites, such as The Library of Congress. If they actually publish a recommendation, it would be highly credible. It would also be about the same as IPI's recommendation.

PPFA has never been a testing agency. The best purpose of PPFA was (and still is) to research the sources of information, then verify and publish recommendations. In that role, PPFA has been unbiased and has served us very well for a long time. Like IPI and Tru Vue, PPFA reccommends 98% in the range of 300 to 380 nm.

FACTS is now owned by the Fine Art Trade guild in London. All of the FACTS standards are about a decade out of date. I hope FATG will invest the time & resources for current research and updates. Meanwhile, FACTS glazing standards won't do you much good.
 
Thanks Cliff, that's a help.

If you or someone has the guide in print, is it too much trouble to scan and email me a pic of that page ? (Email adderess in profile)

Google didn't come up with an online pdf or other source on that, although TruVue has a reference to this (seems just in their acrylic section) at
http://www.tru-vue.com/Framers/FAQ/Acrylic/

That, together with the link Jim sent, is what I will send to Schott.

Cheers,
Les

Thanks Jim, just caught your reply.
Will check US LOC site also.
 
Les, It's a copyright protected publication of PPFA. It can be purchased from them.

I wouldn't feel right copying even just a page.

I don't remember the price, but it really wasn't very much.
Maybe someone in Jackson would be willing to sent you just that page?

Sorry.
 
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