Digital BW, The Print

I've actually seen these Ultrachrome K2 black and white prints shift within the span of a week in an exhibition where fairly bright daylight was present. Not ultra bright, but a bit over 450 lux. I'm not kidding and they were framed behind glass. It was a big embarrassment for the photographer. I'm glad I didn't print them. But I did spray ALL the Ultrachrome prints I did at that time with  with a uv coating and always used QTR to reduce the color content. But it is always there to some degree when you are dealing with brown "gray" inks and trying to achieve neutral color in the whole range. 

I have also seen tests I've had around for a few years on a bulletin board shift, usually toward cyan as the light magenta goes, or toward blue. No chemicals or pollution in my studio. Of course these were not behind glass, or sprayed, but to me that shouldn't be necessary.

john





--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Jon Cone" <jon@...> wrote:
>
> David,
> 
> Mayhaps not, but I would not suspect that you would notice any changes in your work in 5 years. But, it's not black and white like you are trying to make it either. (pun intended).  The threat is relative to the intent of the photographer and the perceived value of their work. For others it doesn't really matter two pickles.