Hi all, If I had said it's nice to see new competition, it would have meant that it's good that Epson has another competitor and I have more choices. gar -----Original Message----- From: DigitalBlackandWhiteThePrint@yahoogroups.com [mailto:DigitalBlackandWhiteThePrint@yahoogroups.com]On Behalf Of failedthespian Sent: Saturday, March 03, 2007 7:37 AM To: DigitalBlackandWhiteThePrint@yahoogroups.com Subject: [Digital BW] Re: New graduated black inks -Blue wool ratings Paul, Regarding you comments and dismissal of the Blue Wool Test, you are out of step with virtually every major organisation involved with testing colour materials for fading. In my experience they all use the Blue Wool Scale and Delta-E values. Additionally, your assertion that you are not a competitor to Image Alchemy also rings hollow. In fact in your email to me of yesterday you state, "... It's always good to see a new competitor". Prior to deciding to manufacture our own inks, we approached a number of different manufacturers including MIS Associates and you. You might recall that I spent an hour and forty minutes speaking with you about the various merits of various manufacturer's offerings. In fact I was referred to you by MISA. Anyway, I need to prepare for PMA, so I cannot comment again concerning this matter. Paul Banks Image Alchemy Ltd www.image-alchemy.com www.image-alchemy.de --- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Paul Roark" <paul.roark@...> wrote: > > > > Our inks are tested to an internationally accepted standard > > the Blue Wool Scale (BWS). > > I just want to comment a bit on the Blue Wool standard. It has been used by > many industries for quite a while, but the Blue Wool test does not appear to > be the internationally accepted standard for photos or inkjet pigments. > > Let me quote Lyson: > > "Lyson has a number of methods for observing pictorial image fading of which > Blue Wool and simple window placement are still carried out. However, the > test that we believe gives the most accurate prediction of actual indoor > display life is the method used by Wilhelm Imaging Research, Inc > (www.wilhelm-research.com). The Wilhelm test criteria has, in the main, been > adopted into the 1996 ANSI (American National Standards Institute) document > 'Stability of Colour Pictorial Images', which itself is in the process of > being furthered into an ISO standard. By definition, this will become the > International test that our industry should orientate itself to." > http://www.nazdar.com/Lyson/lyson-longevity.html > > > I actually have the Blue Wool test materials and decided not to bother with > them. I'm not saying they are not relevant, but they do not give enough > information to distinguish the inks, and testing to the end stage is not > what I'm most interested in and is not practical for me. I do not have the > time to do that for enough inks and papers to allow me to move forward at > the speed this industry moves. > > Let's look at some actual numbers and equivalences. The Blue Wool rating of > 7 is 300 megalux hours of exposure before fading becomes noticeable. (See, > for example, http://www.handprint.com/HP/WCL/pigmt6.html#lightfast) This > translates into 152 Wilhelm years of display. (Wilhelm uses 450 lux for 12 > hours per day.) The Blue Wool rating of 8 (the highest) is 900 megalux > hours of exposure before fading becomes noticeable. This is 457 Wilhelm > years of display. > > Most of the action with respect to the pigments I'm working with is between > the BW 7 and 8 ratings. That is rather large gap -- from 152 to 457 Wilhelm > years of display. > > It also would simply take me too long to test to the end points, and I don't > think that is my main interest anyway. So, I test for shorter periods, but > long enough that the initial high non-linearity I've found with some inks > does not overwhelm the final results. (Most of this is in the first > "Wilhelm" year.) > > As an example, in one test a bit more than a year ago, I exposed samples for > what would be the equivalent of 13 Wilhelm years. In this test the MIS UT7 > did 2.8 times better (looking at the change in Lab L) than the K3 B&W inks > on Premier Art Hot Press (the same coating as UltraSmooth). Wilhelm rates > the K3 B&W inks at ">205" years on UltraSmooth under glass (not UV glass). > So, could the UT7 inks really "last" 574 years in typical indoor display? I > don't know, and I'm not going to do the testing needed to get to that stage. > That would, by the way, be a Blue Wool rating of 8. In fact, Livick did a > test on coated UT inks all the way out to the end point. He came up with a > rating of 681 years. > > Any accelerated test is subject to criticism. They all introduce factors > that might skew the results one way or the other. But when I see most of > the industry going to Wilhelm, that makes his procedures the de facto > standards regardless of their merits. In fact, however, my reading and > experience suggests Wilhelm is the best there is. > > At any rate, I simply want to point out that Blue Wool rating of 7 is fine, > but it does not tell me what I'm looking for. It does not tell me these new > inks are any different than the others that are out there. > > I'd love to see a comparative test. I really hope you do have something > special. > > Epson's Claria "dye" inks demonstrate rather convincingly that significant > progress is possible and perhaps likely in this field. The pigments we use > are called "dye stacks." I wonder what happens when Epson "stacks" the > Claria dyes? Would there be a huge (like 4x) improvement in the pigment > lightfastness the way there appears to be for the dyes in their soluble > form? Would we be looking at color prints with "800 years" of display life? > > Paul > www.PaulRoark.com > Please visit the Group Homepage to check the Files, and other resources as they are often being updated. http://groups.yahoo.com/group/DigitalBlackandWhiteThePrint If you wish to receive no emails or just a daily digest, or you wish to unsubscribe, please edit your Membership preferences by visiting this same page. 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RE: [Digital BW] Re: New graduated black inks -Blue wool ratings
2007-03-03 by Gary W. Weaver
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