Why ink and lighting matter

[ThrillaMozilla]

This is the most amazing tale of rapid fading I can imagine. I wish I had scans, so you could see exactly what I am talking about. I also wanted to run some tests, but I'll probably never get around to it. Oh, well, I've been sitting on this story long enough.

In Sept. 2011 I transferred an LP record to a CD, and I transferred the album cover to paper inserts in a plastic jewel case. The paper was hp multipurpose paper with ColorLok. I also printed matching artwork on a Verbatim DataLifePlus CD. The design had large areas of yellow, with smaller patches of near-primary colors. The printing was done with an HP C309a printer and third-party dye ink (except pigment black for paper).

I leaned the CD in its case against the side of the LP in a brown paper bag, waiting for someone to pick it up. The bag was partly closed at the top. It sat in the corner of the room on the floor, 11 feet (3.4 m) away from a torchiere-style lamp with a 13W compact fluorescent light aimed at a white ceiling. The light was on 24 hours a day. The room faced the north (in the northern hemisphere), with very little indirect daylight reaching the bag. Thus, the room was rather dimly lit. All lighting was indirect, most of it being bounced off the ceiling, through the paper bag and in through the top.

When the owner finally returned for it, almost exactly a year later, CMY were completely faded from the paper on the front and the edge. Only pigment black remained. The back side was partly shielded from light by contact with the LP. Even so, only pigment black and a little bit of yellow remained. There were prominent straight-line streaks, which proved that fading was due to light (visible, UV or IR), not to a chemical agent. The CD itself appeared unaffected by fading.

Two copies were made at the same time were kept in a well-lit south-facing living room, do not appear to be faded at all after almost three years. This room has been lit by a mixture of incandescent and LED lighting, and UV- and IR-filtered indirect daylight. The edges (printed on paper) were continuously exposed to ambient light until approximately February of this year, and yet show no apparent fading.

I'm fairly confident that severe fading was caused by a combination of unstable ink and UV light from the compact fluorescent light, coming in through through the top of the bag and possibly the sides. The pattern of straight-line streaking, and the fact that two other copies in jewel cases did not show fading, appear to rule out chemically-induced fading. Keep in mind that the level of illumination was quite low, and the material was seemingly quite well protected from light. I think I know what kind of ink it was, but my notes made at the time are ambiguous.

Although CDs and photo paper are less subject to fading than writing paper, they are not immune. It appears to me that one mistake could cause catastrophic losses in a surprisingly short time. I have not gotten around to doing further tests, but I am now very careful in my choice of ink, and I have banned all fluorescent lighting, including CFL's, from the house.

 

[The Hat]

Thank you for sharing that freighting experience you had with ink fading and the CFL bulb !
Now that you’re back using Candles again I heard that Bee’s wax are the best ones to prevent further fading…

 

[stratman]

Is it possible that that particular paper in that light source plus gassing from the brown paper bag (or some other source) were responsible for the advanced fading? It may also explain why the image on the disk was resistant to fading -- different media than the Colorlok paper.

 

[ThrillaMozilla]

Stratman, as I said, I didn't get around to running any tests yet. I got tired of sitting on the story. I regret that I let the visual evidence go without making a scan, so all we have is the facts as I observed them.
I have no doubt that light was responsible. The streaks were very clear. I can't be sure that gas from an old paper bag did not contribute, but (1) the jewel case was closed; and (2) the only side that was not completely faded was the side that was shaded by the LP cover (and the bag). As for gas from other sources, I doubt it. There are two computers about 6 m away, but they are also fairly close to the other images (in a connected room) that did not fade. There is also whole house ventilation from centralized heating and air conditioning. Other materials in the two rooms are similar, and there is no other equipment or other obvious source in the room to speak of. So I have no reason to believe that gas contributed, even though I can't prove it.

I've done other tests in which I found that there is much less fading on CDs than on paper. So yes, that is why the paper materials faded so rapidly compared to the CD.


The Hat, I still have some incandescent lighting, but like the Rijksmuseum in Amsterdam, I'm switching to LEDs. I suppose there is a minor concern because they emit a lot of blue light, but for now I'm following the museum's example -- and saving money.

I think there is pretty good reason to suspect fluorescent lighting. In my office I have noticed that some materials have faded rather badly. In particular, there are many labels written with a marking pen, that are no longer readable. This is a BIG problem. At home I have an irreplaceable family picture that has faded noticeably under incandescent light in about 30 years. Not too bad, but I would rather not have any fading at all, and I would be very concerned about changing the light type. And I sure as heck am not going to use any more disappearing ink.

Don't worry, there's probably nothing to worry about as long as you don't print anything on paper or have anything that you care about. We all have different priorities. My concern is that I could have a lot of damage in a short time if I'm not careful.