Digital BW, The Print

"Mark" <mark@...> wrote:


> ...  I'm the primary author of two key published papers related to the subject of humidity induced dye migration in inkjet media. ...
> 
> http://www.wilhelm-research.com/isj/WIR_JapanHardcopy2005MMG_HW.pdf
> 
> http://www.wilhelm-research.com/pdf/is_t/WIR_ISTpaper_2003_09_MMG_HW.pdf
>...

I was curious if I could (crudely) replicate these results with the Noritsu dye inkset, which includes a 30/70 dilution LK version of the dye.  I made prints of resolution charts on Red River Metallic paper and placed them in a sealed jar that had water in it (initially hot to be sure the air was saturated quickly).  This was left for 2 days.

There were 3 types of test strips: Control (not in the jar), "No Spray" (a test strip in the jar with no spray applied after printing), and "Sprayed." (There were 2 different versions of this, one with 3 passes and one with 6 passes of Lascaux acrylic spray.  I've posted only the 6-pass version.)

The bottom line is that I do not see significant resolution reduction in the results.  However, there does appear to be a reduction in density, rather visible in the 50% resolution bars.

I've posted scans of the results.

At http://www.paulroark.com/BW-Info/Dye-Humidity.JPG is a screen grab that shows the basic results, but not in much detail.

Even in this image the density reduction of the 50% resolution bars is apparent.  Using the PS Histogram to measure a selection of the central part of the largest resolution bars, the numbers are as follows: Control = 68, No Spray = 80, Sprayed = 78.  (The higher the number, the lighter the bar.)  The Control test strip 50% resolution bars are noticeably darker visually.

At http://www.paulroark.com/BW-Info/Resolution-Ctrl-no-spray.jpg I've placed crops of the 7.2 and 3.6 lp/mm resolution results.  I don't see any differences here.

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