Is T400 CN permanent?

Does anyone know if T400 CN or other dye based b&w films are as

permanent as their b&w silver counterparts like Tri-X?

Specifically I am concerned with whether they fade in time.

I have also read comments on this forum that they are more easily

scratched.

thanks in advance

C-41 B&W films (like their color counterparts) are not as permanent as archivally processed B&W silver films, but that may just be a matter of degree and not of practical importance to most people. Properly processed silver films probably last hundreds of years (or longer), no one is quite sure. C-41 films can last decades if stored in an ideal environment, and any deterioration is likely to be subtle unless stored at high temperatures or high humidly. C-41 films are still the best way to go if you can�t do your own developing. Just store them in a cool dark place with low to normal humidity.

I'm not a fan of C-41 process B&W films but I would imagine that they'd be much more stable than color films. The dye doesn't have to be chosen for it's color fidelity like it does in color film. The biggest fade problem in color films is that the three layers fade at different rates, and soon you can no longer use them to make a color print with anything like the colors you're wanting. But until we know for a fact that the dye will last as long as a properly processed silver image I'm staying with traditional films.

They won't last as long as a properly procesed & stored silver based b&w film, but if the dye layers do fade, the overall contrast of the neg will change since with a film like XP1 & 2, there are 2 emulsion layers. Can't say what would happen with TCN, but I do have an old Ilford manual that says this is a possibility with their chromogenic b&w films. fwiw, don't forget the film base material as well--some form of acetate--usually gets around 50 yrs or so at normal room temps. So, depending on what you use it for and how you store it, it may or may not outlast regular b&w films anyways. Opinions expressed in this message may not represent the policy of my agency.