Re: Paper negatives- Ink Selection&Baden-Baden
Henk, Another great print! You're absolutely right: it is fun to discuss negatives, inks and paints ... but in the end, surely for gum, it doesn't seem to matter too much. Whatever you do you rely on experience and feeling. Whenever I feel like it I test paper, inks, colloids ... and I now have a bunch of notes and curves. I don't even use them anymore when printing gum or casein, only when printing cyanotype I use a colorised negative (paper or film) and a curve. Groetjes, Guido 2008/10/15 henk thijs <henk.thijs@hetnet.nl>: > I did a lot of paper- and Arista half tone negs; i used negatives for > cyanotype, gum and oilprinting and i was very often astonished about two > things: > the unpredictable (and often astonishing) results ; > the forgiving aspects of too long or too short exposure times doing 'alt'. > It was the list who first mentioned the dramatic effect on exposure times > due to humidity; so i have some experience and do not trust any specific > rules in order 'to make the perfect gumprint or equivalent'; i measure the > amount of paint by eye, vary the exposure by looking a bit after the > humidity, downloaded some 3 dollar tutorials from Dans Burkholder website > for my printer settings and let it go. > Isn't that the way an apple pie is done after years of experience ? > Cheers, > Henk > > Baden-Baden Horse racing Oilprint on 350 grs Fabriano nr 5 with > inkjet-plotter-foil negative (exactly same exposure compared to paper neg ): > > http://www.thijs-foto.com/newDESIGN/baden.jpg > > On 14 okt 2008, at 23:05, Katharine Thayer wrote: > >> Loris, my question was a simple question: on what are you basing the >> statement that your exposure times are shorter than others'? because I'm >> not seeing other gum exposure times in the thread, never mind that even if >> there were, no valid conclusions could be drawn from the comparison. >> Instead of answering the question by pointing to posts I missed, or >> describing the data on which you base the assertion, you simply repeated it. >> It's not a helpful answer to the question, but I won't pursue it further; >> I'll take your word that there are these people you know about, somewhere, >> who print exactly as you print, with exactly the same emulsion, same paper, >> same light source, same negative media and exact same working procedures >> (same environmental conditions, we would also have to assume) who have to >> use longer exposure times because they're using negatives with more DR, or >> they're not calibrating, or their calibrations are flawed somehow. This is >> quite a remarkable finding, as I've never met two gum printers who use the >> same everything, unless they happen to be taking a workshop together and >> are using premixed emulsions and all other materials and equipment supplied >> by the teacher. Oh well, I don't really care, I was just curious. Back to >> check on my print, >> kt >> >> >> >> On Oct 14, 2008, at 11:08 AM, Loris Medici wrote: >> >> >>> Katharine, don't worry I'm pretty careful about this subject - knowing >>> (by >>> experience) you'll chime in every time it's brought up, to clarify ;) I'm >>> getting older I guess; less and less surprises... ;) >>> >>> I wasn't attributing the short exposure I'm using to curves at all, that >>> was a side note (which should have been enclosed between parenthesis, >>> sorry). I was trying to say (indirectly) that since the DR (=density >>> range) and tonal progression of my paper negatives (made with the HP 9180 >>> all-inks grayscale setting, using the printer's plain paper profile) are >>> close to ideal (in tricolor gum printing context - which is supported by >>> the fact that the curve I devised for this particular combination is the >>> smoothest and least dramatic one among all curves I did until now), >>> therefore, other people's longer exposure times could be caused by the >>> fact that they're using negatives with more DR, which naturally will >>> require more exposure and a stronger / more dramatic curve to >>> counterbalance. Or they're not calibrating, or their calibrations are >>> flawed... >>> >>> Hope it's clear, and makes more sense to you now. I perfectly understand >>> the confusion I may have caused on your part. >>> >>> Regards, >>> Loris. >>> >>> P.S. BTW, I have compared my times with the times of people who use >>> similar light source, emulsion, negative media and working procedures. >>> I'm >>> perfectly aware of the parameters affecting exposure time and pay >>> attention to them. >>> >>> >>> 14 Ekim 2008, Salı, 7:18 pm tarihinde, Katharine Thayer yazmış: >>> >>> >>>> >>>> Loris, I'm wondering what data you're basing this last bit on, that >>>> other people's exposure times are longer than yours. It's generally >>>> not useful to try to compare exposure times because there are so many >>>> variables involved, but putting that aside for a moment, I've looked >>>> back through this thread, and the only reference to exposure times I >>>> can find is Guido's comparison between oiled and unoiled Epson PQ >>>> paper, 8 vs 48 minutes, with cyanotype. Since it was cyanotype, and >>>> since the paper is a heavier paper (27 pounds) than yours, it's not >>>> surprising that his exposure time for unoiled paper would be longer >>>> than yours, and we haven't even got to light source yet; to reach >>>> immediately to curves to account for a difference in exposure times >>>> seems rather a long stretch to me. >>>> >>>> Perhaps I've missed other posts that included exposure times for gum >>>> and paper negatives (my server doesn't accept some of the alt-photo >>>> mail, so I don't always see all the posts). At any rate, my times >>>> with oiled paper negatives run close to my times with inkjet >>>> transparencies, about 3 minutes, to add to your database on exposure >>>> times. I don't have any comparison with unoiled paper to offer, >>>> because that's not an option that makes any particular sense to me. >>>> >>>> But be that as it may, I can't see any reason why curves would >>>> account for a difference in exposure time. After all, the exposure >>>> time is determined before curves are even calculated, at least that's >>>> how it is with the system I use, and I assume it's the same with all >>>> systems; the curve doesn't change the exposure time. Besides, curves >>>> simply redistribute the tones within the print tonal range that >>>> particular emulsion can print under that particular protocol; they >>>> don't extend it, so there's no logical reason curves would have any >>>> effect on exposure time. >>>> Katharine >>>> >>>> >>>> On Oct 12, 2008, at 11:23 AM, Loris Medici wrote: >>>> >>>> >>>> >>>>> I use the grayscale using all inks (not black and gray - if present >>>>> - inks >>>>> only), plus, I choose plain paper as the media. Fortunately, with >>>>> my inks >>>>> the printer lays just enough ink giving an almost perfect negative in >>>>> terms of density range (something around log 1.0), and the curve I >>>>> use for >>>>> gum prints are is the least drastic and most smooth one among my >>>>> curves >>>>> collection for many processes and paper. In fact, I think that's >>>>> why other >>>>> people's exposure times are considerably longer compared to mines... >>>>> (!? >>>>> >>>>> >>> >>> >>> >> >> > >
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