Digital BW, The Print

Igor,

>> There is some warming that is normal with carbon inksets. 
>>This has more to do with carbon itself warming up. 
>>It's not that much, however.

>Take a look at http://members.ams.chello.nl/iwesdorp/ut-fs/index.htm
>Here you will see a scan showing 2 small prints: 
>UT-FS on photo rag.  They were printed 4 1/2 months ago on 
>the same sheet of paper.

>The print on the right was stored away, in darkness,
>in an acid-free sleeve. 

There is some blotchiness in the print on the right.  Is that on the print
or a scanning artifact.  It does not appear to be on the print on the left.
I'm wondering what would cause that. 

>The one on the left I keep in a drawer, not
>framed, no sleeve. I took it out every now and then and 
>it was exposed to moderate artificial light (25 watt lightbulb. 
>7 1/2 LW, says my Lunasix light meter).

Is the drawer a wooden one?  What else is in the cabinet?  Wood and the
finish on wood can be a problem if it is out gassing something that the
pigments are affected by.  If there is out gassing, the blotchiness of the
print on the right that was in a sleeve might explain the blotchy affect.

I've had silver prints in metal cabinets be attacked apparently by air-borne
acids that were outgases from other papers in the same cabinet.

>The scan shows quite accurate the difference. The print on the 
>left is quite a lot warmer, and the dark tones has become 
>somewhat lighter. Maybe this will not occur if framed behind 
>glass; I don't know, yet.

>For me that is a very important question. But can you 
>recommend a paper that has the same looks as photo rag, 
>but is not prone to those tone shifts?

I'm not sure what is going on with your prints.  I'm guessing the cyan
pigment and/or paper is being attacked by a gas.  

I don't have great information on the relative resistance of papers to gas
attack, but my perception from what I've read is that Photo Rag is
relatively susceptible and Epson UltraSmooth is more resistant.  I
understand why people love the look of Photo Rag, but I use UltraSmooth and
the Premier Art papers that apparently use the same coating -- Premier Art
Fine Art Hot Press 205 and 325.  For example, I'm just starting another
museum preservation project, and I'm recommending Premier Art 325 for that
one.

> can glass be considered as a UV coating?

It blocks the shortest UV wave lengths, which are the most damaging.  That
is why indoor display has much less of a UV problem than outdoor display.  

The UV sprays still do some good.  In my tests the Epson UC inks under
fluorescent lights get about a 30% better life, and MIS inks about a 10%
better life with something like a Premier Art Print Shield.  The spray
basically brings the UC pigs up to the MIS level, making be believe the MIS
base (which is a light yellow) already includes some UV protection in it.

I don't know if the sprays are effective at stopping gas attacks.  I'd guess
they would at least slow it down.  For the museum project, I'm spraying the
prints, more for physical protection than light or gas, however.

I would avoid storing photos in wooden drawers or with any non-buffered
papers.  Gas attack is a significant problem in some environments, and I'd
guess that is what you're dealing with.

You might want to take a look at the Art Care products.  See
http://palimpsest.stanford.edu/waac/wn/wn18/wn18-1/wn18-106.html,
http://www.nielsen-bainbridge.com/Bainbridge/4NB-ACEndorsements.html, and
http://www.inkjetart.com/misc/artcare/. 

Hope this helps.  It's sad to see your photos deteriorate like that. 

Paul
www.PaulRoark.com