Duotones offer designers a great way to add visual interest to photos. Essentially, a duotone is a way of representing an image (usually a photograph) using a limited number of tones.
The benefits of duotones include:
- Adding color to a black & white photo
- Creating more drama and visual interest in an otherwise basic color photograph
- Allowing you to take advantage of the inks used in a print project
What is a Duotone?
Let’s first clarify what a duotone is. A duotone, as its name implies, is an image made up of two separate tones. When printed on a printing press, these tones are made up of two inks, usually black and another color such as a Pantone color. But duotones can also be made up of two process colors or two Pantone colors. The whole point of a duotone in print is to take advantage of the inks being used in a project. So instead of printing all of the photos in a project as black & white, you could print the photos as two ink colors making them look more aesthetically pleasing and maximizing the inks being used in the project. A common example is when newsletters and other projects are printed using two ink colors (to save money), duotones are often used to make the project look more pleasing. This type of duotone is what I’ll refer to as a “true duotone” as it is actually using two distinctive inks.
Sometimes, designers simply like the appearance of a duotone and decide to use them in four-color print projects, digital print projects, and even web projects. In this situation, the appearance of a duotone is created using the process ink colors. In this article, I’ll refer to this type of duotone as a “fake duotone.” Don’t let the name turn you off. There’s nothing wrong with creating and using this type of duotone effect. It’s just called “fake” because it’s not really using separate inks to achieve the desired result. Let’s take a look at how to create various types of duotones.
Creating a True Duotone
To create a true duotone, you need to use true a grayscale image. If I’m starting with a color image, I won’t just blindly convert it to grayscale mode. To get better results, I like to add a Black & White adjustment layer in Photoshop, and then tweak the tones in the Properties panel to enhance the image before conversion.
Once you’re happy with the appearance of your black & white image, choose Image > Mode > Grayscale to convert the image to grayscale mode and retain the appearance you created with the adjustment layer. A dialog box will appear asking you if it’s OK to flatten the image. Go ahead and do it.
You might have noticed that the Duotone option in the Mode menu was grayed out when you were converting your image to grayscale. That’s because the Duotone function in Photoshop requires you to start with a grayscale image. Now that the image is in grayscale mode, choose Image > Mode > Duotone to display the Duotone Options dialog box. By default, the settings will be set to Monotone. Simply choose Duotone from the Type drop-down menu to change the settings to duotone. By default, your colors will probably be black and white. Click on the white box next to Ink 2 and choose a color. Click the Color Libraries button to access a list of Pantone colors and choose the one that you prefer. In the image below, I’m going for a traditional “sepia tone” look so I chose Pantone 7551 as my color, but you can choose any color that you wish.
You can further refine the tonal adjustments by clicking on the Duotone Curve icon next to each ink. This displays the Duotone Curve dialog box and allows you to make adjustments just like the Curves adjustment does. The tonal values of each ink can be adjusted independently, which gives you a lot of control over the final appearance of the duotone. Unfortunately, you don’t get a real-time preview when making these adjustments so you’ll need to click OK to see the results of your adjustments. You can however continue to go back to the Duotone Curve dialog box as often as needed to continue refining the tonal values of the ink.
Reusing Duotone Settings If you want to replicate the appearance of a duotone on other images, you can click on the small gear icon in the Duotone Options dialog box and then choose Save Preset. This will save the settings, and you can reuse them on another image by choosing the option from the Preset drop-down menu. You’ll also notice a bunch of default presets in the Preset drop-down menu that you can experiment with as well.
Using Duotones for Print Output
A true duotone is an unusual beast when it comes to placing it in another application for print output. First of all, if you try to save this file, you’ll notice that there’s a pretty short list of formats available to choose from. A duotone file can only be saved as:
- Large Document Format
- Photoshop EPS
- Photoshop DCS
- Photoshop Raw
My word of advice would be to have a discussion with your printer to find out what the best format will be for their workflow. You may even be asked to convert the document to a multichannel file (Image > Mode > Multichannel) so that each ink or plate appears as a channel in the file and you may also be asked to save the file in the DCS format. Again, ask your printer for their specific requirements.
Saving a Duotone for Digital Output
The term “digital output” is pretty ambiguous. This can include digital print, web, video, and many other options. The good news is that most of the work is already done. You can convert a true duotone to a “fake” one in virtually any color mode that you wish. For print, web, and video use, you can simply convert the file to an RGB image by choosing Image > Mode > RGB. This will retain the visual appearance of the file but will render the colors using the red, green, and blue channels of the file, just like a typical digital photo. For some projects, it may be necessary for you to convert to CMYK color mode for digital print output. Again, I encourage you to check with your printer to ensure best results. In some cases, they may want an RGB file.
I personally love the look and capabilities of a duotone for print and digital/web projects. The method described in this article is important if you intend to output a true duotone for print, and it also offers a lot of control over the appearance of the duotone. For destinations other than print you have a lot more flexibility and fewer requirements. One example is the method shown by Chad Neuman in this article. When creating your own duotones, keep the final output in mind and choose the method that you prefer.Tags