U of S | Mailing List Archive | alt-photo-process-l | RE: How many gum layers (Re: ferri sesquichlorati)

RE: How many gum layers (Re: ferri sesquichlorati)

"But, I might also enjoy a bit of belt  sanding and a bit of power hosing too"

Mark, for what it's worth, my favorite new tool is a $20 air-powered angled grinder from Harbor Freight.  THAT baby can really do a number on a stubborn gum print!
 -----Original Message-----
From: Ender100@aol.com [mailto:Ender100@aol.com]
Sent: Wednesday, October 25, 2006 11:02 AM
To: alt-photo-process-l@usask.ca
Subject: Re: How many gum layers (Re: ferri sesquichlorati)


I feel like I am starting to answer my own posts here, so here is a short and sweet summary of my thoughts on the topic and I will leave it to others to continue the discussion.

I think I have said a few hundred times regarding gum that I am aware that it is a very different animal than PT/PD.  You can hose it, you can brush it, you can print multiple layers each for shadows and highlights, etc etc etc.   I agree with that.

Setting that aside for a moment, with gum there are adjustments one can also  make to the negative to improve results, so you don't have to do quite as much beltsanding or power hosing—that is IF you want to go that route.  If you enjoy  belt sanding and power spraying, then by all means do it.

Reading back over your posts, such as your response to Sam, where you said that each type of negative would definitely require a different curve, I am not really sure what your take on the whole thing is.

Certianly with a process like PT/PD or other single printing (usually) processes, it really is quite important how you craft your negative, just as it is very important how you manipulate your chemistry, paper, humidity , etc.  But with gum you also  have other things you can do to achieve your goal—all I am saying is that if I can get an edge with optimizing a curve or density range, for ME, I will take that option.  But, I might also enjoy a bit of belt  sandiing and a bit of power hosing too.

Happy gum printing!

Best Wishes,
Mark Nelson

Precision Digital Negatives - The System
PDNPrint Forum at Yahoo Groups

In a message dated 10/25/06 10:50:56 AM, kthayer@pacifier.com writes:

>  " Otherwise, why not just start with an image, invert it and make 
> a negative of any unknown density without a curve and keep fiddling 
> with it until you get what you want in the print."
> Best Wishes,
> Mark Nelson

Well, indeed, why not.   Like Keith, this is exactly my approach and 
as Keith says, it works fine.  And as Chris showed last week, it 
works good for her too.  Her tricolor gum made from inverted uncurved 
channels was cyan-biased, but that's not a function of the curves, 
that's a function of the  selectiion of pigment concentration of the 
three pigments in relation to each other.  So I guess my answer to 
Mark's question "why not?" is,  beats me!  Seems like a perfectly 
reasonable approach to me.

But since Charles posted the link for ChartThrob yesterday, I've been 
playing around with generating curves some myself, and like Keith, I 
have to say, so far I like the "no curve" approach better too.

Recently, Mark, you said that a beginner could save a lot of time, 
money, and materials by investing in a system for generating curves, 
or better yet, two systems.   At the time, that didn't make sense to 
me, because the time and materials you "waste" in the beginning 
learning to print gum are "wasted" in the process of learning to 
print gum, not in the process of generating negatives, and you still 
have to learn how to print gum, no matter how you generate your 
negatives. So I'm not sure how it would make any difference.   And 
besides, the way gum works, there's very little waste; there's almost 
no print that can't be salvaged; pigment stain is the one exception, 
and curves or no curves don't have any bearing on pigment stain.   
But I didn't think there was any point in arguing further, so I let 
that thread die without saying so.

But now, after an evening of printing value templates,  I have to say 
I think the savings are in the other direction; you save more 
materials by printing gum. At least when you're actually printing 
images, you have a print to work with and do something with, and 
chances are you can do something with it, even if you didn't get it 
"right" on the first printing.  But a template of value patches is 
just a template of value patches.  And if I was really going to do 
this, I'd have to do it for every single different pigment I ever 
use, at every concentration I use it at, at every environmental 
condition (humidity, particularly).... I would be doing nothing but 
printing templates for the rest of my life, and there's not a thing 
you can do with the stupid things, except generate curves.  Talk 
about waste of materials!  I'd rather be printing gum.

I can't say yet whether the resulting curves would be an improvement 
over the uncurved negatives; I'm not even there yet.  Will report in 
due time with a comparison.