Richard,
>... transparency material is definitely not all the same when it comes to the amount of ink it can accept. ...Only UltraPremium OHP could deal with the ink load from 2-4 inks for ever point on the scale. ...
I suspect the old Pictorico film and White Film I have used is a different coating than their ";Ultra." If ink load looks like an issue, I'll have to try that one.
As I've suggested, what I'm seeing in used in the alt process field is not needing all that much density. I was, frankly, surprised. On the other hand, what I'm wondering is whether most aren't punching through the toe or shoulder of their materials, and that may be needed to wring all that is there out of the approach.
If more density is needed, I will see what the (unexpected) ability of my glossy carbon setup to print MK onto film without smudging can do. That is part of what initially sparked my curiosity here. I don't think the MK on glossy has much, if any, use in normal inkjet printing because the reflective dmax goes down. However, being able to sprinkle (actually two channels in my wide format printers) of MK onto the glossy substrate (that also has about twice as much PK on it) can build very high transmission density. The high carbon load of the MK ink can increase the amount of carbon on the film per fluid base. Unlike reflective work where the gloss surface becomes a major factor, limiting loads, for transmission density the total carbon load seems to keep stay fairly proportionate to transmission density for significantly longer.
Paul