How to Make a Duotone
Rich, textured and emotive, two inks make a better halftone
By John McWade
Dateline: December 19, 2003
The invention of the halftone in 1883 was a technical and artistic miracle. Ink, which previously had been applied in solid sheets, could now be printed in tiny dots that the eye perceived as shades of gray. The result was an illusion of dimension that made the printed photograph possible and changed the way the world communicates.
But the modern halftone could use some improvement. Shades of gray are no match for the sheer variety in our natural color spectrum. Contrasts of hue, saturation and intensity, for example, do not even exist in black and white. What the halftone could use is greater tonal range.
To achieve this, a duotone is made of two halftones, not just one, and printed in two inks. Two halftones double the printable range of an image. The second halftone is usually a second color, and is usually balanced differently (its shadows may be light, for example, while the originals are dark). Even better, a duotone has a rich color cast that endows a photo with a sophisticated air unavailable even in four-color printing. Heres how its done:
Photoshop makes a duotone by superimposing two halftones, one of which is (usually) printed in black, the other (usually) in color. The halftones can be identical, but more often theyll be different (below). Its important to note that a good duotone can be made only from a good halftone; a second ink can color but will not improve a muddy or washed-out image. Youll get the best results with the least effort from a photo whose tonal range is evenly distributed from dark to light (right).
Here, two halftones of the same image are slightly different; the top will print black, the bottom blue. The lighter blue will keep the dark areas from becoming overly dense.
A Duotone in Three Steps
Duotone inks are always spot colors, and the Ink 1 color is normally black (the default). To set your second color, click its color swatch (right), which brings up the Custom Colors dialog. From its Book submenu call up a color library (ours is Pantone*), then to find your color, scroll the palette or simply type its number. Click OK (twice) and watch what happens. To modify your results, select Duotone again from the Mode menu, and repeat.
*Pantone inks are solid colors. Our examples are simulated.
What Makes a Good Second Color?
Keep in mind that on most jobs your second color will also be used to print other elements type, for example, lines, or a backdrop from which lines are reversed. Your choice, therefore, should be strong enough to stand on its own. For the easiest duotones, use pure, bright colorsreds, violets, greens and such. Deep colors are the most versatile. They stand alone well for type and other elements, and when lightened make beautiful duotones. Its easier to lighten a colorjust tint itthan to darken it, which requires adding black.
One Color Should Dominate
By adjusting the amount of color in the halftones, you can dramatically change the look of a photo. Reducing percentages of color (near right) progressively diminishes the influence of the blue, changing the scene from watery to moody. Similarly, lightening the black (far right) hints at misty morning. To do this, recall the Duotone Options dialog (select Duotone from the Mode menu), click the curves icon next to your color, and in the dialog that pops up (below) enter a value less than 100try 50%in the 100 box. This lightens the colored image by half. Click OK and check the results.
(You can alsogulpbend the curve. Youd do this, say, to keep color out of too-dark shadows.)
Duotones Without Black...
This article is excerpted from Before & After, How to design cool stuff, Issue 27, Vol. 5, No. 3, and is reprinted here by permission. Copyright ©2003, Before & After magazine, all rights reserved. Design more cool stuff! Visit Before & After magazine online at http://www.bamagazine.com/ to buy the current issue, subscribe, or order back issues, including the one containing this article.