Digital BW, The Print

--- In DigitalBlackandWhiteThePrint@y..., SKID Photography 
<skid@b...> wrote:

(snip)
> 
> But I must take issue with the 'acid pen' and the 'buffered' pspers 
statement.
> 
> I still maintain that buffering has, so far, shown itself to be 
detrimental to inkjet inks and also, that if
> the paper has an acid component (using wood pulp instead of cotton, 
or 'rag' fibers')  the buffering agents
> will be overwhelmed in the long run and self destruct.

Harvey,

There are many qualities that determine a good paper. One is the pH 
of the paper as a measure of acid content which is easy to check with 
the pH test pens. Another is that the paper be lignin free, which is 
not so easy to measure. Lignin is the component in wood pulp papers 
that breakdown into acid compounds and cause yellowing. Quality wood 
pulp papers are made that are lignin-free and are the equal to rag or 
cotton paper in permanence. The lignin free wood pulp papers are 
preferred in many applications as there are stronger than rag papers.

Buffering is added to lignin free, acid free papers to form an 
alkaline reserve to protect them from environmental conditions that 
would cause the papers to become acidic.

Quality papers are made with out buffering that will last as long as 
the buffered papers if not subjected to outside sources of acid.

Non-buffered papers are required for use with dye based materials as 
color dyes will react badly with the buffering agents. Dyed textiles, 
dye transfer prints and I imagine dye-based inkjet prints should not 
be used on buffered paper to ensure image permanence. I believe that 
the "Archival" in EAM has to do with image permanence and that the 
paper was designed to work with the Epson 2000P.

A high quality lignin-free, acid-free paper without buffering will 
have a pH of about 5.5 to 6.0 and will test acid with a pH test pen. 
This is the situation with silver fiber paper, which will test right 
on the threshold of the pen. EAM tests on the acid side of the 
threshold but is probably an acid-free paper in its manufacture. From 
its stiffness I would be very surprised if EAM was not a wood pulp 
paper.

While I agree with your point about non-buffered papers and image 
permanence for dye based ink sets, I think that buffered papers are a 
better way to go with the carbon pigment quads. A lot of fade testing 
has been done with the carbon pigment inks on a number of papers and 
there does not appear to be any relationship between the buffering 
and image permanence from the information we have. So unless you know 
that the buffering will effect image permanence, you are better off 
going with the buffered papers that offer protection from 
environmental contamination.

Also keep in mind that the vast majority of art papers being used for 
inkjet printing is buffered. Hahnemule, Crane, Legion, Brightcube, 
Hawk Mountain, etc. are all buffered papers. If you want non-buffered 
papers the choices are pretty limited. 

The other quality of a good paper to consider is the presence of 
optical brightening agents of OBA's. These add to the image range but 
will yellow with time. The yellowing of EAM in Paul's fade tests is 
probably due entirely to the decay of the OBA. Crane's Museo, which 
has no OBA's, did not yellow. Other papers use varying amounts and 
yellow to different degrees. The decay of the OBA's will be in direct 
proportion to the amount of UV they are exposed to.

There is a huge amount of information on paper permanence. If you 
check the Files and Bookmarks sections there are some links.
> 
> Those old photos were, in general, made on rag papers that were 
acid free to start with, and then, over time
> they have encountered acids in the atmosphere, causing the 
degradations.

You could see marked differences from different time periods. The 
1840's paper was still white but the papers from the late 1800's and 
into the early 1900's were in bad shape. If it was strictly 
environmental, then some should have been ok and others not, but they 
all showed decay. It was not so much that they were yellowed but that 
they had turned dark chipboard gray, which I suspect was caused by 
the use of wood pulp in the paper. Whatever the reason it was very 
sad to see.

> 
> It is my feeling that if one wants long term stability (like on the 
old photos) one should use rag papers,
> which have slight amounts of buffering agents in them...hopefully 
enough to neutralize acid atmosphere over
> time, but not enough to degrade the inks...Unlike wood pulp papers 
that achieve ph neutrality only because of
> large amounts of buffering agents.

Rag is a good choice but like I said you can make a high quality, 
lignin-free, pH neutral wood pulp paper that is the equal to rag.

Martin Wesley

(snip)