Creating Duotones
for Printing and Web Pages

The two "sepia" duotones above were created with Black and Pantone 471, the burnt orange color seen here on the left.

One of the nicest features about Photoshop's Duotone mode is that, even though a second (and separate) ink color is added, the file size remains the same. That is, when you turn a 10 MB grayscale file into a duotone, the file size remains at 10 MBs. Of course, when you turn a 10 MB grayscale file into RGB mode it becomes 30 MBs (and into CMYK mode it becomes 40 MBs). This savings does translate into some limitations, however. The duotone's settings can be only one way throughout the image and there is no possibility for variance. Therefore, the top photo of the Pictograph image, which shows different density ramp combinations of each of the two colors used, could only be created in RGB mode, after creating five different duotone files and copying and pasting them (by sections) into a RGB file. And the lower photo of the snowy river scene could only be achieved in RGB mode because of the neutral gray area in the lower center (which demonstrates how much color is involved in this duotone). First the duotone was created (in Duotone mode) and then the mode was changed to RGB and the gray square area was selected and completely de-saturated.

The top photo of the Pictograph shows that there are many choices in making a duotone because you have complete control over the density ramps of each color involved. When you initially go from Grayscale to Duotone mode you first have to select Duotone under "Type". This activates the "Ink 2" density ramp and color boxes. Clicking on the color box will bring up the "Custom Colors" window which allows you to pick the Pantone color you desire. Clicking on the density ramp box brings up the "Duotone Curve" window which allows you to alter the density ramp of the second color. Of course, you can change the color and density of the "Ink 1" color the same way.

The duotone above was created with Black and Pantone 3135, the turquoise color on the right in the previous illustration

The vertical strips on the Pictograph photo are all made with the same two inks (black and Pantone 471) - the density ramps of the two inks is what varies. From left to right the first strip is completely grayscale, no duotone involved. In the second strip, a very subtle duotone, the density ramp for the color ink has the 100% density mark set to 30%. This means that where there is 100% black in the grayscale image there will also be 30% color and, accordingly, where there is 50% black in the grayscale image there will also be 15% color. The "Show Info" window states how much density there is of each color when the pointer is placed over any particular area of the image. In the next strip the density ramp for the color ink has the 100% density mark set to 50%. At this point, we have to lighten the density ramp for the black ink to compensate for the density of the color ink, or our duotone will be too dark when printed. Therefore, the black ink has been set to 95% at the 100% density mark in the density ramp. In the next strip the color density has been set to 70% at the 100% density mark and the black ink density has been set to 90% at the 100% density mark. The more color ink involved, the more you need to lighten the black ink density in order to have a duotone that doesn't loose shadow detail when printed. In the next strip, both the color and black inks have been set to 85% at the 100% density mark. In the center strip, the density ramp for the color ink - set at 100% at the 100% density mark - is stronger than that for the black ink - set at 75% at the 100% density mark. The vertical strips to the right of center are mirrored reflections of the duotone settings on the left side.

In the middle photo of the girl with the oranges (taken at the market in Merida, Yucatan) the duotone settings are the same as in the third strip of the Pictograph - the density ramp for the color ink has the 100% density set to 50% and the black ink has been set to 95% at the 100% density mark. This is a fairly common setting for duotones in general and is very similar to the exposures given to film when a traditionally-made duotone is created. In order to keep this image's brightness, a slight lightening of the midtones was then applied with a Curves adjustment. A little more color is involved in the duotone of the snowy river scene - the density ramp for the color ink has the 100% density set to 65% and the black ink has been set to 93% at the 100% density mark. A slight lightening of the midtones was then applied with a Curves adjustment in this duotone as well (there were no Curves adjustments done in the Pictograph duotones)

Compare the brightness of your duotone to the original grayscale file to see whether you should do a Curves adjustment or re-adjust the density ramps of the two colors. Obviously, the color chosen for the second color of a duotone will have a lot to do with its final appearance - the more saturated the color is the more it will color-tint the original grayscale image. Generally duotones are made with black and a second color but can be made with a primary color other than black, like dark brown or dark blue, but this may tend to shorten the tonal range of the image rather than enlarge it.

Duotones must be saved in EPS format to import into page layout programs. When getting negatives output on an imagesetter for offset printing, get a color key or matchprint made to double check how your duotone settings worked and see if your printer is satisfied with your results (before printing). For web pages, after creating your duotone you should save the file in Duotone mode in case you later want to adjust the density ramps. Create a new file and go to RGB mode and then save in JPEG format (or GIF if preferred) - once you leave Duotone mode you cannot go back but must go to Grayscale mode (loosing all color) and start over again. Of course, you can save your Duotone settings and it's a good idea to do so, especially if you are offset printing your results. You can then load the settings when making duotones of other black and white images so that they will all be consistent, if you desire.

IN MEMORY OF CARL VOLK
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>>>>Carl N. Volk<<<< April 8, 1953 - September 5, 2000

Carl's art, talents and teachings will live on for all of us to enjoy.
Visit: http://www.carlvolk.com