Re: Printing gum with little pigment

[Katharine Thayer <kthayer@pacifier.com>]

On Jan 19, 2009, at 5:35 PM, Marek Matusz wrote:

> Katharine,
> It is clear that lower pigment concentration will result with lower  
> DMax, and lower density range which you have nicely illustrated.  
> The real question that I asked can not be really answered well with  
> a real negative, because if you develop for highlights a number of  
> shadow steps can be blocked, which can be difficult to spot on a  
> real negative.
Umm, what?   I suppose that might be a valid criticism if the  
exposures hadn't been carefully predetermined to yield the maximum  
DMax and maximum number of steps for each mix with no blocking and no  
lost highlights,  keeping the development time constant, but since  
they were, I'm not sure I understand how the suggestion fits here.    
(Perhaps you didn't read the text that accompanied the visual... ) At  
any rate, I was careful  to make clear that I wasn't suggesting that  
the density range can serve as a substitute or an approximation for  
the number of steps, since there is no correlation between the two  
for gum as there is for some other processes.   It's just too bad I  
didn't keep the step tablets that I used to determine the correct  
individual exposures and standard development times for each mix,  
since that's what you want to see,  but at the time, the number of  
steps for each pigment mix wasn't that important to me, as long as  
I'd made sure that the chosen exposure and the standard development  
yielded the maximum possible number of steps for the mix, whatever  
that number was, and I tossed them after they had served their  
purpose of calibrating the printing so that I could be sure the  
comparisons were valid.
Katharine