Tone your shot: Duo-, tri-, and quadtone images

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“Hans Weichselbaum discusses the many options when it comes to split toning your images to achieve your desired look and feel”

Black-and-white printing never went out of fashion after the introduction of colour film in 1936. On the contrary, it has staged a comeback in fine-art photography. This is not surprising — who does not appreciate a well-balanced monotone landscape or portrait image, printed on fine-art paper?

We all enjoy a colourful slideshow on the big screen, but monochrome images need to be printed. Most, if not all, award-winning black-and-white images hanging in galleries aren’t black-and-white at all — they are duo-, tri-, or quadtone prints. The subtle colour tints give them the extra depth and richness.

Split toning

You have probably come across the Split Toning tab in Adobe Lightroom or Adobe Camera Raw. Whereas a black-and-white adjustment layer allows you to add an overall tint to your image, split toning simulates a duotone effect. In Image 1, I have given the shadows a blue tint to emphasize the freezing winter temperatures. Then the highlights were blended into yellow to simulate a late-afternoon light, giving the image some overall warmth.

With the African scene (Image 2), I did the opposite: I chose a brownish tint for the shadows, and a bluish hue for the highlights. In the black-and-white conversion ahead of the split toning, I pushed the yellow and the green sliders all the way up to maximum to get the surrounding greenery as light as possible, making the elephant stand out.

For split toning, it is best to start with the highlights, because the effect is easier to see. Move the saturation to around 40–50 and search for a hue that looks the best for the highlights. Then reduce the saturation to get an overall pleasing effect. Then do the same with the shadows. The balance slider allows for a final adjustment.

For a conventional black-and-white portrait, you’ll probably want to give the highlights and shadows different hues of brown, but nothing stops you from going wild and wacky by creating blue/green Martians. This technique even allows you to simulate a tritone effect by adding a tint to the entire image before starting with the split toning.

Don’t forget that you can also run a PSD, TIFF, or JPEG file through the Adobe Camera Raw module. Simply use the Open As command and select Camera Raw for the file type.

Starting in black and white

I can’t see any reason for setting your camera to black and white. Even if you have a final black-and-white print in mind, you might change your mind and regret having thrown the colours away. Secondly, it is very dangerous to leave the black-and-white conversion to a machine. Only you can decide what greyscale tones the foliage and the skin tones should have in the final picture. This is no problem if you shoot in RAW, because the camera will record all information anyway but beware if your camera is set to JPEG.

It also goes without saying that we never simply switch the colour mode from RGB to greyscale to convert a colour image to black and white. Adobe Photoshop (and any other image-editing software worth its salt) will give you ample control over how the individual colours are translated into shades of grey.

The portrait (Image 3) was converted into a black-and-white image (Image 4) using a black-and-white adjustment layer in Photoshop, in which you can adjust the tonality of six colours. Camera Raw and Lightroom give you eight colours to adjust (Image 5). You can also select one of the presets — for example, a green filter for portraits or a yellow or even red filter for dramatic effects.

Don’t forget the old Channel Mixer, which has tended to be neglected since Adobe introduced the black-and-white adjustment layer. In the following example, we’ll work with the Channel Mixer.

Start with a colour image (I’ve used Image 3) and create a Channel Mixer adjustment layer. Enter 75-per-cent red, 25-per-cent green, zero-per-cent blue, and tick the monochrome box (Image 6).

Then create a new layer and choose Merge Visible from the Layers menu. Next, you need to make a selection of the part of the image you want to colour. I chose to work with the Select > Colour Range menu and selected Midtones (Image 7). The range sliders allow you to narrow or widen the range, while the fuzziness slider also lets you influence the transition between the shadows and highlights. I gave it a heavy feather under the Refine Mask interface, too.

The next step is to make a new layer and add a layer mask. The new selection will automatically appear as a mask. Now choose a nice sepia colour as the foreground (for example, R: 172, G: 122, B: 51) and hit Fill from the Edit menu.

Finally, adjust the opacity to your liking. I ended up with Image 8. You can repeat the process with different shades for the shadows and highlights.

Duo-, tri-, and quadtones

Besides the common greyscale, RGB, and CMYK colour modes, you’ll also find a mode called ‘Duotone’ (Image 9).

Duotones are useful for a number of reasons. Firstly, they will save on printing costs if you take your images to a professional printer — two inks cost less than four. Secondly, you can create some seriously high-end–looking black-and-white prints.

‘Duotone’ refers to an image of two colours (black is usually one of the two). Photoshop’s Duotone mode lets you add special colours to genuine greyscale images. Adding two colours gives you a tritone, and, you guessed it, a quadtone image has got three colours on top of greyscale.

How do we access this magic mode? First, you need to convert your images to black and white — by using a black-and-white adjustment layer, for example. Then change the image mode to greyscale and let Photoshop flatten your file. Finally, choose Image > Mode > Duotone.

At the top of the Duotone Options dialogue box, select the colour combination you want. Photoshop gives you dozens of duo-, tri-, and quadtones to choose from in its Preset menu. When you click on one of the settings, Photoshop shows you the chosen ink combination, and you get a preview of your image. Image 10 shows the Duotone mode at work.

Of course, you can mix your own colours by choosing Duotone, Tritone, or Quadtone from the type menu, and then click on the little colour squares below the menu to pick your inks. You can save your combination by giving it a name, and Photoshop will add your new recipe to the Preset menu.

If you click on the square to the left of the ink, Photoshop lets you peek in on how this ink will be applied in your image. If you’re brave enough, you might want to tweak the curve (Image 11), similar to the Dot Gain curve in the CMYK interface.

Once you are done, head back to Image > Mode and choose RGB. Because duotone is a special mode meant for printing (not editing), you don’t want to hang around there. Once back in RGB, you won’t notice anything different — except the awesome new colours of your image.

Multichannel colour mode

This is the last on Photoshop’s long list of colour modes. If you switch from RGB (or from CMYK) to Multichannel, only three channels show up in the channel palette: cyan, magenta, and yellow — no black and no combined channel.

But nothing prevents you from creating a new channel — for instance, by combining the cyan and magenta channels, possibly with the Multiply blending mode, and turning it into a new black channel. You can even swap channels, say magenta with cyan, and create some cool surrealistic images. In the distant past, when colour scanners costed a fortune, people used to scan colour images three times through red, green, and blue acetate. The three images were then combined into a single multichannel document and turned into RGB.

Today, satellite and astronomical images can gather electromagnetic radiation outside the visible spectrum: infrared, UV, and radar. This additional information can then be added to the image and shown as ‘false colour’ images.

In normal photography and printing, the Multichannel mode also has its applications as an intermediary step for complex spot-colour images. It can be used to store extra channels for transparency masks or selections in other images. Multichannel images can only be saved in the PSD, RAW, or large-document formats.

RIP software

If you don’t own the latest printer technology, then an RIP will be your answer. This stands for ‘raster image processor’ and is software that replaces the print driver. Professional RIPs cost more than the average A3 printer, but, fortunately, there is QuadToneRIP, developed by Roy Harrington, which is very affordable (Image 12 shows its interface).

This is a huge bonus for black-and-white printing, and it was my preferred route for producing superb monochrome prints for a long while. I used this RIP for many years, but found that Epson UltraChrome HDR inks can give me 100-per-cent neutral grey tones without the need for an RIP.

This article will have shown you that there is more to black-and-white photography than meets the eye. The first rule is to not allow a machine to do the black-and-white conversion for you — only you can decide how every colour should be represented on the greyscale spectrum. Most people stop at giving their portrait shots a nice sepia tone, but some go further and discover split toning, or go one step on from that and work on the mid tones only. Finally, duo-, tri- and quadtone printing opens up an almost infinite field of opportunities to turn a simple snapshot into a work of art.