Paper, wetness of pen/ink, humidity, temperature, UV exposure, ozone level, and high levels of air pollution are all factors that can cause fading of ink, and in many ways increase the challenge of making an ink fade test that is relevant to different parts of the world. I think one of the issues with the many UV tests that are done on this forum is the lack of understanding of what the resulting fading means for writing that is not being exposed to such intense light, such as something that is in a closed journal on a shelf or drawer. Does that fading represent 10, 20, 50, 100, or a 1000 years of light, ozone, and temperature exposure to something that gets less than a percent of these same variables. If you think about it in lumens, the light hitting a window is 10's to 100's of thousands of lumens, the light hitting a paper on a desk is single digit to double digit lumens, and barely any in a dark desk drawer. Fading by ozone is dependent on your location, major cities through air and chemical pollution often have higher levels than rural non-industrial communities. Awhile ago, I looked at UV exposure, and found that a document being exposed to 50 lumens of light a few hours a day would take a thousand years at least to experience the same effect of UV that a document attached to a window for something like 5-6 months is exposed to. My overall concern with these tests, is that we don't really have a great idea of what they mean, because we cannot relate the result back to a period of time it would take in normal use to have this fading occur. Some inks are well known to fade within a few months, but many conventional inks do not fade within many decades. Knowing, and controlling the variables I have mentioned will allow us to better understand the longevity of conventional inks in everyday use, but until then, I find it problematic to take a great significance from these tests for everyday use.
Edited by JakobS, 07 December 2017 - 17:54.
FP Ink Orphanage-Is an ink not working with your pens, not the color you're looking for, is never to see the light of day again?!! If this is you, and the ink is in fine condition otherwise, don't dump it down the sink, or throw it into the trash, send it to me (payment can be negotiated), and I will provide it a nice safe home with love, and a decent meal of paper! Please PM me!For Sale: TBA