[Tutorial] Duotone Images with Photoshop

Today’s tutorial is about creating Duotone images in Photoshop. These are grayscale images with 2 colours. Their main advantage over purely black based grayscale pictures is an increased dynamic range and they tend to look better.

Duotone imaging is mostly used when you are limited two 2-coloured printing or simply want to print with 2 colours only (eg for cost reasons). You may also apply it to optically spice up black & white pictures with more depth by adding an additional colour.

If you aren’t constricted by a limited number of printable colours you can even improve your image with Tritone or Quadtone processing. Basically the same like Duotone, only with three and four colours. At the end of the process you can switch back to CMYK or RGB, depending on wether you want to print it (CMYK) or use it digitally (RGB). There’s more about that later on.

Enough talk. Time to show how you easily convert plain black & white images into striking Duotone, Tritone or even Quadtone artworks.

My chosen base image is an interesting picture of an elderly Afghan man (with thanks to ©AfghanistanMatters on flickr)
You can, of course, choose any other picture which you think might look good in black & white.

The first step is to make some adjustments to the image. Depending on the quality of your starting material you can optimize as much as you like. In this case I go to Image > Adjustments > Brightness/Contrast and increase contrast a bit.

Especially portraits often ask for a bit more sharpness to improve definition of delicate lines and facial features. Via Filter > Sharpen > Unsharp Mask you get to the right setting options.

Activate the Preview option to more easily find the best setting for your image or use the settings shown above.

Photoshop offers hundreds of ways to convert you image into black & white and almost everyone has a favourite. To keep the tutorial short I chose the easiest way. Go to Image > Adjustments > Black & White.

If you don’t want to use the settings in our screenshot (Preset: darker) you can play around a bit until you get to a good outcome. Just be careful that the image doesn’t become too dark or light. It should also retain the character of the basic image.

At this point we have to go a little detour to get into Duotone mode (which is unavailable at the moment). Go to Image > Mode > Grayscale and confirm the dialog.

Depending on your Photoshop version this dialog might look different but it always asks you if you want to discard colour information. Yes, you do.

Duotone mode is now available in the Image > Mode menu. Clicking the option you get a dialog to create your Duotone image. The dialog already offers some presets but you can create completely individual variations by clicking the colour field in the row for print colour 2. Besides choosing the colour it’s also possible to adjust the Duotone graph to influence colour intensity.

As mentioned above you can also turn the image into Tritone and Quadtone mode. Simply select the option you prefer. Try some of the presets for those or apply values provided in the screenshots below.

If you prefer to print it as 2 colour image you can save it in Duotone mode. This is not very common but useful when you have a black & white document with only your company Pantone based CI colour. You can import the Duotone image into InDesign and proceed as normal. In our print calculation mask you would set the colour option to 2/2-colour Black + Pantone.

To use the image for standard printing or as digital format you need to change back to RGB or CMYK mode. Any CMYK colour profile can be used for commercial printing but for best results with our machines we recommend ISO Coated v2 (Fogra 39 L).

It’s time now to try around a bit. Have fun! :)

Duotone

Tritone

Quadtone

MO/SdP