Digital BW, The Print

Right, I meant 50 lux museum lighting at 34 megalux hours (the conservation rating end point for the average patches of this media on your test) = 161 years for Chrystal Archive in very low light levels.

At 450 lux (average illumination) it drops to 17.4 years.

At a bright window light,5000 lux it drops again drastically to 1.6 years.

And exposed to a south facing window like a store front 10,000 lux you get 6 months (if your lucky). This all is the average of all patches and does not tell what would happen to the 3 worst colors in the color chart that would do far worse.

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It's interesting that Wilhelm's long published results for Chrystal Archive shows it at 450 lux to have an end point at 40 years or 50 years behind uv glass. That is a long way from 17.4 years that your site reflects. He's allowing for a greater rate of fade (35% ?) before reaching the end point which your saying is way too far and too noticeable? That is the way I'm reading it.  And I don't think he is factoring in the burnout of the optical brighteners. At any rate he's being generous it seems to me.

Ok, I'm through giving away your information. From now on we all need to pay for it regularly. Just wanted to make that more clear if I could. I'm trying to learn also.

john