Duotone

So what is a Duotone?

A DUOTONE is a halftone image printed with two colors, one dark and the other lighter. The same photograph is halftoned twice, using the same screen at two different angles. Combining the two improves the detail and contrast in the final printed image. (source: http://www.printingyoucantrust.com/glossary.cfm)

A halftone is a continuous tone image photographed through a screen in order to create small dots of varying sizes that can be reproduced on a printing press. Digital halftones are produced by sampling a continuous tone image and assigning different numbers of dots, which simulate different sized dots, for the same effect (source as in above.)

To put it simply, you combine two monochrome colors (2 = Two = Duo, gets?) to an image to produce the color effect you desire that is different from the original, say, Black and Yellow or Black and Blue. However, one color need not necessarily be black. You can choose, Yellow and Blue or any of the color combinations available in Photoshop.


Step 1: Open the image you want to use in Photoshop. I selected this image of an island in Tahiti published in the web.



Step 2: Take out the colors and go B-W by selecting on the menu bar Image > Mode > Grayscale.

Click on Ok when you are asked to discard color information ;-)


Step 3: This is our first Duotone: Black and White! Since our image is now in Duotone we can then experiment with other colors. Go to menu Image > Mode > Duotone.

You now have Duotone options. You can set this feature to Mono-, Duo-, Tri- or Quadtone.

Step 4: For this exercise, select Duotone. The first color, by default, is Black. You can select another color if you want later on to see various toning effects. Now, you can go to the second slot and choose a second color by clicking the second empty square. You have a variety of colors to choose from. To see an online preview, tick the box next to the Preview label. Click OK when you are satisfied with your color combinations. I chose PANTONE Process Yellow C for the second slot as shown below:


Click OK.

Step 5. Go to Image > Mode > RGB to be able to save your newly-colored image as JPEG, GIF etc. Now save this image using File-Save As in the menu bar. After naming the file and pressing Save, you will be asked for the JPEG resolution. Choose, Low, Medium, High etc. depending on your needs.
I chose PANTONE Process Yellow C with Black and here's what I got:


Here are other Duotone samples of the same image:

PANTONE 484C and PANTONE Process Yellow C

PANTONE 105C and 304C: