How to Print Richer Black and White
When you take a look at a well printed traditional black and white print made on glorious old fibre based paper you will see an extra depth of black which gives the print a certain richness. If you have ever tried to make B+W prints on an inkjet printer, especially starting off with a colour digital image, then you may have been slightly disappointed with the result.
Inkjet printers can only print a black of a certain density, this is known as the D-Max of the print. This can vary from printer to printer, inkset to inkset and from paper to paper. Using Epson Ultrachrome K3 inks on a top quality paper like Hahnemule Photorag or Arches Soft Cotton will enable you to get a black that will rival that of a traditional silver gelatin B+W print.
However, D-Max does not tell us the whole story, it is the way that the tones of a print progress towards black that also affects how the print looks and, whilst Curves and Levels allow some broad control over these tones, there are better ways to control what are sometimes referred to as the ¾ tones.
A Greyscale image in 8 bit comprises 256 ‘colours’, all of which are grey. An RGB image in 8 bit comprises 16.7 million colours so it follows that the RGB image will have far more subtlety of tone than a simple greyscale image. If we take an RGB image and simply desaturated it so that each colour is the same value we will have a B+W image in RGB but we are back to 256 tones again.
There are many different ways of making a colour RGB image into a good B+W image but I want to look at making a decent B+W image that will easily print with some of the richness that you would expect from a silver gelatin print but using no fancy software, just good old Photoshop.
1. Open a RAW image into Photoshop Adobe Camera RAW. You can make it into a quite decent B+W image by simply changing the Saturation slider to –100. The image I am using for this tutorial has a really nice sky and I can exaggerate this by using the ‘Calibrate’ tab and increasing the Blue Saturation. In this shot it makes the sky look as though it was shot on B+W film using a red filter. Click Open to bring the file into Photoshop.
2. At first glance the image looks fine but if printed it will be lacking a certain zing. We could add contrast using Curves but that would affect the whole image and in this image we risk burning out the very bright beach. I want to add contrast to the sky and richness to the blacks but leave the highlights alone.
3. Choose Image | Mode | Greyscale to convert the file to a true single channel greyscale. This will not change anything visually, it is just a necessary step to make before the next one – you cannot convert directly from RGB to Duotone.
4. From the same menu, now choose Image | Mode | Duotone. This brings up the Duotone Options dialogue box. In ‘Type’ you should see Monotone which is the same as greyscale, monotone = grey. Click in the drop-down box and select Duotone. Now you will see ‘Ink 2’ appear below ‘Ink 1’. The image will not change yet because we have not selected a second ink to use to tone the image.
5. Click in the solid white box in the ‘Ink 2’ row. This will bring up the Colour Libraries Palette from which you can select from a bazillion different inks! In the Book drop-down list I generally use the Pantone Solid Coated set and usually look for a nice deep blue, something like ‘Pantone Reflex Blue C’. Click OK and your image will change to a rather dark blue tone – don’t worry, we have another couple of steps to go yet.
6. We are using a dark blue because a deep blue/black looks and prints richer than a straight black. However we don’t want blue highlights, only slightly blue shadows and ¾ tones. The Duotone Options dialogue should still be open and in the ‘Ink 2’ row there is another white box with a diagonal line running through it. Click this box to bring up the Duotone Curve dialogue, the heart of this whole process.
7. This is where you control which tones are affected by the new blue ink colour. We only want the shadows to be blue and we don’t want to have an abrupt transition from neutral grey to blue/black. In the percentage boxes type in the following values: 60% : 2, 80% :30. The line will now change to a smooth curve, gently increasing from about 50% and heading up quickly to 100%. You can also drag the curve if you choose.
8. This curve depicts which part of the image is getting a blue ‘boost’. There is no change in the pure whites (0%) through to about mid grey (50%). As the image tones get darker, so more blue is applied until 100% which has the most blue added. The preview will show the effects and you can ‘season to taste’ using my figures as a starting point. Click OK to apply the effects and OK to change the image into a Duotone.
9. We need the image to be in RGB to make a proper print so simply select Image | Mode | RGB Colour to take the image back to your RGB working space for printing. To print, simply print the way you would normally, using the Print with Preview option and make sure you apply the usual colour management options. The print should be rich and punchy with a subtle hint of blue through the shadows.
When you compare the two images, before and after, you will see immediately the dramatic difference in tonality with the duotone. The highlights should still be clean and bright but the shadows and ¾ tones are now substantially richer.
Of course you don’t have to use blue as the second colour, choose a nice deep orange colour to get excellent sepia tone prints. There is nothing to stop you using a 3rd or even a 4th colour for TriTones and Quadtones. The possibilities are endless.
Tip: You can adjust the curve of the ‘Ink 1’ channel too, this means you can add some contrast to the grey tones for extra snap.
Tip: When you are happy with a curve you can save it for future use, or even as part of a batch action to process multiple files.
Tip: Photoshop ships with some preset Duotone, Tritone and Quadtone curves. You can load them in the Duotone Options dialogue box and they should be found in the Adobe Photoshop CS2 folder in Presets | Duotones.
Nick Rains 2006
