Digital BW, The Print

My initial idea for doing this was based on using a set of piezotone  
carts for the 1280 with QTR. Since the two lightest grays are  
duplicated, ie: two channels each, it took some conniving to get  
things to print acceptably with all six channels.  Before I knew  
about the copy curve function, I simply set up two four channel  
curves, using one pair of mid-grey/light-grey channels for one curve  
and the other pair for the other.  Then, to print I blended the two  
curves 50/50.  The result was generally smoother than the individual  
curves. By printing the ink separation page in the QTR setup through  
the finished and blended curves, I was able to verify that the output  
of the two mid-grey and two light-grey channels were approximately  
halved in order to produce the proper ink density for the same range  
of each of the individual curves. Hence, the light bulb in me brain!

I'm not so sure that having multiple channels with Eboni would kill  
the white of the paper. The general way I was going to approach the  
problem was to produce a curve and linearization for a single  
channel, then copy the curve to the duplicated channels.  Then, to  
control the density of the multi-channel output, I would use a little  
trial and error with the ink limits. Therefore, at no point in the  
combined curves would any one channel be producing full output.  Just  
as a guess, it seems that if you had four channels, the ink limit for  
each for maximum dmax would be around 25%.  In essence, the benefit I  
envisioned would be that any failings in the output of one channel  
would be offset by one of the others.  And, since the density would  
be produced by adding multiple "layers?" or more accurately, more  
concentration of ink, there would still be virgin paper visible in  
order to produce the gradient.

I think the bottom line is that I've got to get me a printer to play  
with, and a densitometer to linearize the curves properly rather than  
fiddling with my scanner. Then when I've got some results rather than  
theory I can see if this is plausible or just a side effect of an  
overactive imagination ;-P

Will definitely keep you posted on my results.

Eric
www.ericashworth.net