Interesting results...
Canson Platine is not doing that well in these measurements...
and indeed the RC's are doing exceptionally well...
The current WIR testing Protocol especially misranks RC media (indeed any papers that contain both TiO2 and OBAs) for three significant reasons: 1) inadequate weighting of media whitepoint color changes in the overall score, 2) loss of OBA fluorescence artificially propping up the WIR yellow patches fading without accounting for the same yellow shifts adversely affecting other highlight colors (e.g., very light grays, blue skies, etc) not represented in the WIR color test target, and 3) failure to account for further ongoing light-induced media discoloration happening to the test samples in dark storage well after the light exposure test step is finished.
The current Aardenburg testing protocol also misranks RC media scores for reason #3), i.e., failure to account for further ongoing light-induced media discoloration happening to the test samples in dark storage well after the light exposure test step is finished.
The Aardenburg site has been pretty dormant for the last year, because I'm spending as much volunteer time as I can on sorting out this post exposure dark storage staining issue, and incorporating the results into a more expanded test report that will provide additional information on light exposure, dark storage, and combined light/dark storage factors. Ultimately, to distill the results down to a simplified (but not oversimplified) "Conservation Display rating" for each printer/ink/media combination requires an additional year or two of ongoing testing for every paper prone to this type of media discoloration. Fortunately, many of today's media do not exhibit the problem. Unfortunately, many do!
The I* metric used at Aardenburg Imaging & Archives to measure color and tonal accuracy is not at issue here nor is the current Aardenburg 30 patch color target design. The current test target has enough color patches to flag the additional color changes, and the I* metric will correctly weight the changes into the score. What's at issue is the continuing monitoring of the color patch values as light fade test samples are retired to dark storage with pre-existing light exposure doses, and how to present all this additional data in a logically implemented test report. This expanded testing sequence greatly extends the length and complexity of the testing, but I feel it absolutely must be done if printmakers are to be given a more complete and truthful "archival" story about today's modern printers, inks, and media. The printer/ink/media combinations chosen for the
Aardenburg Inks and Media testing 2017 campaign will be the first published results to incorporate our "new and improved" test methodology.
RC photo media are going to take a particularly big hit when this improved Aardenburg testing methodology gets published because essentially all of them suffer from additional post exposure dark storage and/or low intensity display yellowing problems.
kind regards,
Mark
http://www.aardenburg-imaging.com