Digital BW, The Print

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Paul" <roark.paul@...> wrote:

> My initial conclusions from this is that these dyes on this paper may not get visibly softer with high humidity, but there may be a serious fade issue.
> 
> FWIW
> 
> Paul
> www.PaulRoark.com
>

That's the first instance I've heard of for humidity-induced fading. Usually, the high moisture content causes both lateral and vertical migration in the coating, but the lateral bleed can be thought of as "dot gain" which usually causes density increases exceeding any decrease that might be occurring by continued vertical migration deeper into the media. That said, my humidity-fastness research was done a few years ago, and the RC photo type papers have been getting increasingly sophisticated subbing layers to draw off the solvent. These "improvements" may be contributing to your observation of density loss. Also, as I understand it you are experimenting with solvent modifications to the Claria Black dye, so you are breaking new ground there! 

 You might also want to rerun the experiment with an older matte paper type like HN photo rag to see if your fading observation is repeated with this dye set.  All in all, dye based inkjet is problematic where high color and tonal accuracy retention is coveted. Typical consumers for the latest wireless "all-in-one" desktop printers that claim "photo lab quality" output are less fussy about these matters apparently.



regards,
Mark
http://www.aardenburg-imaging.com