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2007-04-05 by CDTobie@aol.com
Kayenta is a wood fiber paper... its just buffered. If your all-cotton Entrada starts to yellow, then I'd start to worry... C. David Tobie Product Technology Manager ColorVision Business Unit Datacolor Inc. CDTobie@... www.colorvision.com ************************************** See what's free at http://www.aol.com. [Non-text portions of this message have been removed]
2007-04-06 by djon43
Yes, Kayenta's derived from wood fiber, but I wonder if the better modern wood fiber isn't actually BETTER than cotton. Kayenta, for example, seems much better than Epson Enhanced Matte, from a whiteness point of view..at least in my environment. Cotton's just another fiber. We have always been taught that it was wonderful, but that isn't necessarily still true :-) Wood fiber requires treatment to become neutral (why do we assume cotton doesn't?)...I've seen a bunch of unattractive cotton fiber paper recently. Why do we want variations on EEM? I think most of us hated that look in silver paper. Presumably recycled would be the ultimate, bleached and washed as well as microchips and Pendleton shirts are.
> Kayenta is a wood fiber paper... its just buffered. If your all-cotton > Entrada starts to yellow, then I'd start to worry... > > C. David Tobie > Product Technology Manager > ColorVision Business Unit > Datacolor Inc. > CDTobie@... > www.colorvision.com > >
2007-04-06 by Richard Smallfield
At 08:48 AM Friday 4/6/2007, you wrote: >Kayenta is a wood fiber paper... its just buffered. If your all-cotton >Entrada starts to yellow, then I'd start to worry... So there really is a difference between acid & lignin-free alphacellulose and cotton after all? I was under the impression that they had the same archival properties. thanks, Richard -- http://smallfield.vze.com http://photos.smallfield.vze.com (Photos web site) http://warkworth.vze.com/ (Warkworth photo essay) http://picasaweb.google.com/rsmallfield/ (Recent work) "I have come to believe that the whole world is an enigma, a harmless enigma that is made terrible by our own mad attempt to interpret it as though it had an underlying truth." --Umberto Eco
2007-04-06 by CDTobie@aol.com
In a message dated 4/5/07 11:34:26 PM, djon43@... writes: > > Wood fiber requires treatment to become neutral (why do we assume > cotton doesn't?) > Treatments to add buffering agents to attempt to make up for the acids present... not ideal; having both acids and buffers present is not the same as avoiding the acids in the first place, as cotton does. C. David Tobie Product Technology Manager ColorVision Business Unit Datacolor Inc. CDTobie@... www.colorvision.com ************************************** See what's free at http://www.aol.com. [Non-text portions of this message have been removed]
2007-04-06 by amadou diallo
I think we should be more specific with terminology here. Alpha cellulose is a treated woodpulp that is generally accepted in the paper industry as having very favorable long term stability characteristics. Of course there are always qualifiers with regard to quality of materials and chemical process, but the reputable paper manufactuers all have access to alpha cellulose material that, according to everything I've read recently should not cause alarm among photographers and others concerned with print longevity. There are papers that are a mix of alpha cellulose and cotton. The economic benefit of alpha cellulose for paper vendors is that it is a less expensive alternative to cotton. -- amadou diallo Author, Mastering Digital Black and White www.masteringdigitalbwbook.com
2007-04-06 by Jim Doyle
Well Put Amadou.. Jim Doyle Shades Of Paper 600 Deer Rd Unit 4 Cherry Hill NJ 08034 856-795-7780 HYPERLINK "http://www.shadesofpaper.com"www.shadesofpaper.com _____
From: DigitalBlackandWhiteThePrint@yahoogroups.com [mailto:DigitalBlackandWhiteThePrint@yahoogroups.com] On Behalf Of amadou diallo Sent: Friday, April 06, 2007 10:13 AM To: DigitalBlackandWhiteThePrint@yahoogroups.com Subject: Re: [Digital BW] Re: Kayenta yellowing too! I think we should be more specific with terminology here. Alpha cellulose is a treated woodpulp that is generally accepted in the paper industry as having very favorable long term stability characteristics. Of course there are always qualifiers with regard to quality of materials and chemical process, but the reputable paper manufactuers all have access to alpha cellulose material that, according to everything I've read recently should not cause alarm among photographers and others concerned with print longevity. There are papers that are a mix of alpha cellulose and cotton. The economic benefit of alpha cellulose for paper vendors is that it is a less expensive alternative to cotton. -- amadou diallo Author, Mastering Digital Black and White www.masteringdigita-lbwbook.com -- No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.5.446 / Virus Database: 268.18.26/748 - Release Date: 4/5/2007 3:33 PM -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.446 / Virus Database: 268.18.26/748 - Release Date: 4/5/2007 3:33 PM [Non-text portions of this message have been removed]
2007-04-06 by CDTobie@aol.com
In a message dated 4/6/07 10:18:28 AM, amadiallo@... writes: > I think we should be more specific with terminology here. Alpha > cellulose is a treated woodpulp that is generally accepted in the > paper industry as having very favorable long term stability > characteristics. > Yup, thats the type of wording that makes it seem great. When I hear it described from the other end, as acidic wood pulp buffered to attempt to postpone yellowing and deterioration, its sounds less wonderful. Alpha cellulose is one of those great marketing terms, like subprime mortgages, that sounds impressive on the surface. If I was convinced that the material itself was neutral pH at the end of the process, I'd be thrilled, but I keep hearing about putting lots of buffering agents in there, which to me implies that there is still an acidic base material involved. Perhaps we should call it "Variable-Rate Sub-Prime Sub-Strate"... or maybe we should just print our good images on cotton-based media. After all; Kayenta was developed as a proofing paper for testing your images before printing them on Entrada. C. David Tobie Product Technology Manager ColorVision Business Unit Datacolor Inc. CDTobie@... www.colorvision.com ************************************** See what's free at http://www.aol.com. [Non-text portions of this message have been removed]
2007-04-06 by Paul Roark
>So there really is a difference between acid & lignin-free >alphacellulose and cotton after all? >I was under the impression that they had the same archival properties. The main longevity problem with wood-based papers is the lignin, which is the hard substance that allows the trees to grow tall. Cotton has none. The lignin produces acidic byproducts as it breaks down. If the lignin is totally removed, the resulting "alpha cellulose" and cotton-based cellulose would, I believe, have the same properties with respect to longevity. Cotton fibers are longer, making the cotton paper better for some purposes. This would include where bending is involved. I think, all else being equal, that the cotton matte papers also absorb the water better than alpha cellulose. The paper company reps don't necessarily agree with me here, but I seem to see more blotchiness on alpha cellulose papers than on cotton papers. My observations may be the result of other differences, however. An example of this would be the Innova-coated Permajet cotton-based "Alpha" paper v. the U.S.-Innova version of the same paper that uses alpha cellulose as a base. I think the problem with cheap wood-based papers, including, apparently EEM, is that the lignin is not totally removed. Lignin is photo sensitive and turns brown itself, regardless of buffering. So, even if a paper meets the standard of < 1% lignin and > 2% buffering, that lignin will yellow with light exposure. The old darkroom fiber-based papers were generally high quality alpha cellulose, I believe. It can be good if well processed. Paul www.PaulRoark.com
2007-04-06 by djon43
http://www.hp.com/products1/printpermanence/pdfs/acid_lignin.pdf Unresearched marketing lore (re: wood pulp, acidity, buffering etc) seem increasingly avoided by the more credible sources (such IMO as Inkjetart.com and HP). Some "experts" are unaware of the central role of lignin. The worst offender is, of course, Wilhelm. --- In DigitalBlackandWhiteThePrint@yahoogroups.com, CDTobie@... Alpha > > cellulose is a treated woodpulp that is generally accepted in the > > paper industry as having very favorable long term stability > > characteristics. > > > Yup, thats the type of wording that makes it seem great. When I hear it > described from the other end, as acidic wood pulp buffered to attempt to postpone > yellowing and deterioration, its sounds less wonderful. > C. David Tobie