Lightfastness test update

[paulr]

In July 05 I started an informal, lazy lightfastness test. All I did was take a few different print samples, cut them in half, and tape one half to a window that gets skylight all day long and a couple of hours of direct sun each day, simulating nightmare conditions for work hung on the worst possible wall. The other half is in a dark flatfile drawer for comparison.

Samples were:

1: a stepwedge printed with piezography warm neutral inks with the portfolio black ink (non archival pigments added to the darkest black) on Hahnemuhle photorag

2: same, but varnished with Golden Paint aqueous UV blocking varnish

3: a silver print on Forezo, toned in selenium and nelson gold

4: a platinum print on an unknown rag paper

5: a c-print from the drugstore, printed on Kodak Royal paper


Results from a year or so ago: no changes on either of the ink prints or the silver print, other than some scuffing on the unvarnished ink print. virtually no change on the c-print (this was the biggest surprise). slight yellowing of the paper on the platinum print, but no change to the image.

Changes as of today:
-no change on the varnished ink print.
-very slight lightening of the darkest square of the unvarnished ink print. it might be due to scuffing against the glass. it's barely perceptible when viewed under plexiglass right next to control sample.
-the c-print has finally gone to pieces. It's faded a bit and taken on a pronounced yellow cast
-the platinum print's paper has continued to yellow. it's not objectionable, but noticeable compared to the half that's been in the dark. the image is still unchanged.
-the c-print's paper, on the other hand, has gotten a bit brighter. it seems to have been bleached a bit by the sun. no noticeable changes to the image.

Samples are back in the window; I'll try to remember to look at them in another year or so.

[Oren Grad]

Thanks for the update. Any change in the Fortezo print?

[paulr]

Oh, I wrote that wrong. Where I said "the c-print's paper, on the other hand, has gotten a bit brighter. it seems to have been bleached a bit by the sun. no noticeable changes to the image," I meant to say "the silver print's paper ..."

So yes, the fortezo paper base got bleached a bit, but the image is fine.

What's actually curious about this is that the papers that have optical brighteners (Fortezo, Hahnemuhle) did not yellow, but the natural paper did. This is the opposite of the results in some older tests.

But I do remember some online tests (on livick.com?) that found hahnemuhle to yellow less than some un-brightened papers.

[David Luttmann]

Good example of what inkjet printing is now able to accomplish. I haven't had any of mine fade at all over the years. Even the dye based Canon prints that I coated and have behind glass are fine.

[Oren Grad]

This sort of informal, real world test is a very useful complement to the better controlled but somewhat artificial results from Wilhelm. Thanks for going to the trouble and for sharing your results.

[paulr]

No trouble at all. Every year or so I remember they're in the window and take a look.

The hard part will be remembering to report back a hundred years from now, which is what everyone will want to hear.