Archived posting to the Leica Users Group, 2013/06/07
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]By the way, the silver print is no longer the top dog for archival B&W.
Carbon is king. See the fade test data, below: (I'm not sure how the
formatting will hold.)
Aardenburg Imaging (http://www.aardenburg-imaging.com/) uses summary
metrics that are probably not familiar to most. The "I* Color" measures
the extent to which color has shifted. "I* Tone" measures only the Lab L
(relative grayscale density) shift. Both of these are weighted to take
into consideration human perceptual characteristics. The Delta-e, of
course, is the familiar total color and tone (Lab A, B, and L) shift, not
weighted by our visual perception characteristics. With the I* Color and
I* Tone, the higher the score, the better. 100.0 is perceptually perfect.
With Delta-e, the lower the better.
Aardenburg Imaging fade test results at
50 MLux-hrs of exposure:
I* Color I* Tone Delta-e
Ilford Galerie FB Silver
Average 90.9 98.8 1.4
Worst 71.7 97.9 3.2
50% test patch 94.8 1.0
Ilford FB selenium toned
Average 92.5 98.8 1.2
Worst 75.5 97.4 2.8
50% test patch 96.2 0.9
"Eboni" 100% carbon on Premier Art 204 gsm paper
Average 100.0 99.0 0.3
Worst 99.8 97.7 0.6
50% test patch 100.0 0.2
Note that this carbon ink sample is now at 120 Mlux-hrs, and the 50% test
patch results are identical to what is shown, above, for 50 Mlux-hrs. (I am
the proud inventor of this inkset.)
Paul
www.PaulRoark.com
On Fri, Jun 7, 2013 at 5:39 AM, Chris Williams <zoeica at mac.com> wrote:
> Europe gets all the cool kids.
>
> http://www.ilfordlab.com/
> ...