Some lightfastness test results

[paulr]

I've been doing an informal lightfastness test for a little over a year now ... some prints and step wedges cut in half, with one half taped in a sunny window and the other in a drawer. It's been 14 months now, and I thought i'd share the current results.

selenium toned silver print--fortezo grade 3: no visible change

platinum print--not sure what kind of paper: paper bleached during the first two weeks, shifting the image tone to a cooler color. no visible change after that.

carbon inkjet print--piezo inks with portfolio black (metal compound enhanced deep black) on photorag: no visible change, except some scuffing/burnishing of darkest tones where print rubbed against window.

varnished carbon inkjet print--same as above, with several coats of airbrushed uv-blocking varnish (lascaux fixativ plus golden aqueous varnish): no visible change

c-print--kodak royal paper: no visible change for first six months. finally after a year, the sky faded and shifted radically toward yellow. areas of the print with more density show much less change.

Unfortunately I don't have any color pigment inkjet prints to test.



they're back in the window. i'll check them in another year.

the most surprising result i think is the c-print. not that long ago i remember c-prints being completely destroyed by an afternoon worth of direct sun. whatever they've done differently seems to work.

[Michael Graves]

So, Paul...

Do your neighbors ever ask if you've taken a whole picture, or if you specialize in half-frame?

Seriously, though, this is an excellent "real-world" test of the resiliency of prints. I for one am interested in following your progress. I would have liked to see a non-selenium toned silver print added to the mix, but it's too late now.

[paulr]

I did started this test on such a whim that I wasn't very thorough about it. It would have been great to get ultrachrome print or two into the mix, but it was all just stuff i had in my drawers.

Just an assumption, but i think the selenium has very little effect on lightfastness. I bet if the silver print ever shows degradation from this, it will be the gelatin first and the paper base second.

i should have added that masking tape holds up poorly ... don't build your next house with it.

[Kirk Gittings]

I am frankly surprised only by the results on the Portfolio Black Piezo print. That does not jive with what I hear from a good friend who also prints on photorag. he has experience significant fading and color shift compared to the Museum Black. I don't know specifics.

[paulr]

Kirk, there's was a lot of controversy surrounding portfolio black a year or two ago. some people were screaming at cone, saying that the black faded in a matter of months.

It turned out that the people having the problems were using RIPs with custom curves, and they weren't laying down the ink according to cone's recommendations. aparently the black ink needs to be sitting on top of a certain amount of the lighter carbon inks. if the portfolio black is sitting directly on the paper, for whatever reason it becomes very unstable.

my primary reason for doing this test was to see how long the portfolio black held up. and to see if varnishing made a difference. i didn't even bother with the museum black, because that's been torture tested to death in much harder tests.

[Kirk Gittings]

That is very good news because the museum black has a pretty sucky Dmax.