In article <322491F8.8DF@earthlink.net>, savagegibson@earthlink.net says...

>Probably for the same reason that they don't sell it in bulk rolls. As
>you can imagine, it is very sensitive to even the slightest light
>leaks.

Hmmm, for a film with a true (shadow-based) ASA of about 650-800,
I don't think that there should be much problem with TMZ, with
reasonable care. Heck, I bulk-load Tri-X all the time, and use
it at a true speed of 800 (shadow-based) with Acufine developer
without problems. The speed of TMZ is vastly over-rated, I think.
There is a difference between useable density on a negative, and
good tonal range (with real shadow detail). Most any 400-speed
film can be used at 1600-2000 with loss of quality, as can TMZ.
(Tri-X can even look good at 1600, if you are into water-bathing.)
Hope This Helps