Process and Materials for digitally printed negatives?

[Drew Bedo]

I am looking at producing ULF negatives from my computer/printer with the view to doing some contact printing in sizes larger than 8x10.

I don't even know what questions to ask.

Can someone a(gently) give me an overview or suggest where to research this?

[Vaughn]

Holy Banana Peels! If someone can give you an adaquate overview in 10,000 words or less, that person is a teaching genius! The carbon forum I participate on deals around 90% on making digital negatives via inkjet printers. The last few carbon printing workshops I have given used digital negs -- but I had a partner that handled all the testing and computer work required. Someone might have figured out a simple way to approach it by now, but I doubt it -- it requires a good working knowledge of PhotoShop and all that...beyond me. My workshop partner died, so all my workshops now will be taught using camera negatives.

The first question would be what printer do you have and what inkset are you using. Second is what process you will be using to make the prints. Then the roller coaster ride begins. Good Luck!

[Peter De Smidt]

One resource: https://www.bwmastery.com/

Inkjetmall has some systems/info for this.

[Alan9940]

Not many details on what you're trying to do, but...

Generally, folks use pigment ink printers to output digital negs on to a substrate such as Pictorico. The PS process to produce that digital neg is varied and alt process workers use many different techniques to get there. I print pt/pd and use the tools referenced to by Peter above. I've tried most of the processes out there, except the latest from Inkjetmall, and find that the QCDN tools provide the best neg for my needs.

Good luck!

[alan_b]

The carbon forum I participate on deals around 90% on making digital negatives via inkjet printers.

What forum is that - can you give a link?

[Jim Andrada]

Mark Nelson has a good eBook available - Precision Digital Negatives

It's pretty involved. The basic issue is that black inks don't uniformly block light of varying frequencies as well as a real silver negative does.

[Alan9940]

FWIW, I used Mark’s PDN system for years and it’s very powerful—especially with the generation of hybrid curves—but it’s also somewhat complicated and difficult to understand. Also, in my experience with it results can vary for no apparent reason requiring re-calibration. All that said, it’s a beautiful system when (if) you get it dialed in correctly.

[sanking]

Making digital negatives with inkjet printers does requires a good knowledge of PS. But if you know PS learning to make good digital negatives for a specific process, assuming you already know the process, can be done in a day of instruction.

There is no standard industry protocol for optimizing and standardizing results with digital negatives similar to those that exist for making monochrome or color prints with inkjet printers. The result is that there are a number of options for creating digital negatives, and understanding the pros and cons of each system must be discovered through personal testing, or by doing a workshop with someone with expertise. Making a good digital negative is much more complicated than just inverting a digital file and printing it on a piece of transparency material. In nearly all cases this procedure will result in a negative unsuitable for your process, either because the contrast is too low or too high, or print output is not linearized, or both.

There are basically two major methods of creating a good digital negative workflow with inkjet printers. The first method is the colorized, or “spectral density” method, which can be used to make digital negatives with most Epson, Canon and HP photo printers. This is one of the earliest methods used to make digital negatives with photo printers and was first introduced by Dan Burkholder in Making Digital Negatives for Contact Printing, and farther developed by Mark Nelson in Precision Digital Negatives for Silver and Other Alternative Processes, and by Peter Mrhar in Easy Digital Negatives. Unfortunately, methods that use the standard printer RGB printer drivers are limited in their ability to control the amount, and color, of ink that is deposited on the film. The result is that in many cases a very abrupt Photoshop .acv curve must often be applied to the image file to produce a print with a linear tonal scale. Abrupt curves can drive up local contrast, and in some cases cause posterization.

QuadToneRIP (QTR) is a separate printer driver, available only for Epson photo printers, that allows for much finer control of how the inks are used. QTR is a raster image processor that allows the user to control the amount of ink deposited on the negative from each of the printer nozzles to exactly match the density requirements of the process, linearize the curve at the printer level, and balance the use of the UV blocking inks to assure smoothest possible results. This gives us the ability to optimize print output to support different kinds of printing solutions in terms of density range and linearization with custom profiles. Ron Reeder was the first to promote the use of QTR for making digital negatives, but the “Reeder” method is just one of several that has been used to successfully create profiles for digital negatives with QuadToneRIP. Other methods include PiezoDN, which requires a custom all-gray ink set, Richard Boutwell’s Quadtone Profiler, which can be used to develop QTR profiles with the standard Epson UltraChrome K3 or HD color inks, and my own single gray value system which I teach in carbon workshops, and describe in the Files section of the carbon forum I moderate on groups.io, is used by quite a number of carbon printers. Details are in a folder at https://groups.io/g/carbon/files/QTR...bon%20Printing

Sandy

[Drew Bedo]

Sandy: Thanks for that overview. Its the type of response that I was looking for.