Paolo Saccheri shares settings used for making digital negatives and highlights the difference the software can make.
What printer settings should be used for creating digital negatives?
Many print makers ask what are the correct printer settings to use to print their digital negatives. The real answer is that there is no fixed true answer. It all depends on your process, i.e. the sum of all the variables you have when printing.
Each printer – which is a variable of the process – has a set of inks and a printer driver that will give you a different print from another printer, and so a different UV filtering ability. We may certainly say that each printer combined with the printer settings and the software you use to print, plots a different UV filtering curve which means your result will be different if you change something.
In a specific printer driver, you can choose from many different settings like the colour space, the paper type, and how it manages colours, and each setting changes the rendition of colours in the print, and therefore the UV filtering curve (more on that later on).
In my tests with my Epson P600 I used different settings in the printer driver and also used different software to print from (Photoshop, GIMP, Adobe Color Printer Utility) to see the differences in the final print. Each test gave me a different result.
Inside Photoshop I have printed 7 strips of a 21 grey step tablet on a transparency film, changing paper type and colour management settings in the printer driver for each print, in order to see what differences in density (UV filtering) those two settings can give.
I tested different paper type settings while printing on my transparency film:
- Premium Luster
- Premium Semigloss
- Paper Glossy
- Premium Glossy
And different colour management options:
- Photoshop manages colour
- Printer manages colours
In my test, for my process, i.e. the sum of all the variables I had, including the printer, Printer manages colour wins for now, together with Premium Glossy paper. My decision was taken upon several considerations including the exposure scale I wanted to get, which is related to the paper white point (more on that later on).
It is a test you may need to make if you don’t have paper white in your print, or if the correction curve you get out of your test print is too strong/rough. You may be able to find out, during the calibration of your digital negative, if one or more printer settings combined make the print of your negative denser than another or the correction curve smoother, which is better. I also tested other settings inside Photoshop, like the Color Mode “Adobe RGB” or “NO colour management“. Some prefer using NO colour management, but for my process, it is not a good choice.
The actual version of GIMP (at the moment of this writing) doesn’t allow you to choose whether “GIMP manages colours” or “Printer manages colours”, the way you can choose inside Photoshop.
Adobe Color Printer Utility (also known as ACPU) is a system used to print with NO colour management. The problem I had (inside Windows) is that the print was done at the upper and leftmost point of the film and I couldn’t find the way to print it more centred, nor in 1:1 scale. So, not good for me.
How to test and select the best printer settings
To find your best printer settings you need to reach the point in the calibration process where you test print the step tablet to generate the correction curve.
Before that, following what I teach in my video course Digital Negative for Alternative Photography, you need to have done the following steps in the calibration process:
- Found your Standard Exposure Time
- Found your Optimal Color Blocker
- Found paper white at the right point
- Printed the negative of a plain 256 step tablet file with your optimal colour blocker on top
The best settings are the ones that give you the smoothest correction curve, given you have paper white.
As you will be able to find through experimentation, if you use EDN calibration system, is that the EDN Optimal Color Blocker LUT file helps to have a smoother correction curve because of how it is engineered.
In my case, the best negatives are the last two (highlighted in yellow), printed with GIMP and with Photoshop. You will notice that the correction curves are in some parts already almost linear (adjacent to the diagonal line, which is where the correction curve will have to go after the linearization).
It is not important for you to copy my settings because as I said they are right for my process (which is the sum of all my darkroom variables, not only the emulsion type I use) and so it might be better for you to do your printing tests if you want to get the best out of your calibration process.
I printed the same file using different software. It is a plain 256 step tablet with the same Optimal Color Blocker LUT on top. As you can see, the colour reproduction on the transparency film is very different, as well as the correction curve coming out from a test print made in cyanotype using those negatives.
Printer settings and Paper White
An important step in the calibration process of your digital negative is reaching paper white. You want to have it in the last steps of the step tablet, but sometimes you can’t reach it.
Letting alone that you may not see Paper White because you have staining problems from your emulsion and development, there is a printer setting that is important to check to get Paper White. Unfortunately, it is a setting not all printers have, the Color Density level.
Paper white is as important as the correct exposure time, because with those two calibrated points at the extremities of the exposure scale of your alternative photographic process, you enjoy all the gamut of shades it is able to give. Then it is you who decides if having or not white in your photo, and so in your print.
Some inkjet printers have very dense inks, pigment-based inks and not dye-based for sure, which are dense enough for non-demanding processes like the Classic Cyanotype, but some alternative photographic processes like Platinum Palladium for example have very long exposure scale and the normal ink density is not enough. That is because with Platinum Palladium you need to expose for a long time to reach the darkest color, and so you need a very dense negative to block light in the highlights for all that time so to have white on your print.
Some photo inkjet printers in the higher end have a setting called Color Density (or a similar name for brands and models different from my Epson P600). With that setting you can lower or raise the quantity of ink that the printer will lay on your transparency film, allowing you to match the density range of your negative with the exposure scale of your alternative photographic process.
To get Paper White, in case you have a printer where you can’t change the Color Density (i.e. ink quantity) and its inks are not dense enough for the purpose, you have two possible solutions.
- You may try to use the Optimal Color Blocker tool offered by EDN calibration system. In case you have a printer with dye based inks, it is possible that some color ink or a mix of color inks will give you a higher UV filtering ability. EDN uses its colorizing tool in a highly engineered way when you use the color LUT file over your negatives.
- You print your step tablet test print using a shorter exposure time, until you reach Paper White.
So, if you want to go into such detail, try to have fun with these tedious tests!
Remember that it can be frustrating at the beginning but very rewarding in the end.
Always remember that the calibration process for your digital negatives needs to be performed, keeping firm all your darkroom and printing variables (including the Relative Humidity (paper humidity) you have while performing your tests.