InDesign Tip: Tinting Grayscale Photos
Changing the colors of photographs in your InDesign project requires Photoshop, right? Not necessarily. If the photo is black and white and saved in grayscale mode in a compatible format, you can tint it directly in InDesign. You can even assign it two colors for an attractive duotone.
A duotone is an image with two colors or tones, effectively a grayscale image, but more accurately one that substitutes a color for black and another color for white or negative space. For example, sepia, a popular effect wherein the main ink is a shade of brown atop a yellowed or off-white background color, is a duotone. While there are varying definitions for the term that have evolved over time, the technique I demonstrate below reflects this interpretation.
Tinting photos in InDesign is easier and faster than working in Photoshop, and it offers more flexibility and freedom for experimentation and adjustment. While tinting in Photoshop gives you superior control because you can use Curves to alter which shades of gray are replaced by which color, tinting in InDesign is a simple duotone process to replace both black (ink) and white (background) with different colors. Here are a few quick steps to get you started. Note that while I'm demonstrating this technique with Adobe CS4, you can accomplish the same thing with previous versions of the software.
Prepare the image. First, you need to use Photoshop to convert your color photo to grayscale (if it isn't already), and save it in a format that supports grayscale mode--a TIFF, JPEG, or PNG will work. To convert a color photo to grayscale, use the Image->Mode->Grayscale command and then save the image.
Place the image. With a document open in InDesign, choose File->Place, load the image, and click on an empty area of the document page or pasteboard to drop it into the page.
Tint the image. Make sure the InDesign Swatches panel is visible (if it's not, choose Window->Swatches). Use the Selection tool (the black arrow) to select the image's container. This is the frame that contains the image, not the image itself. On the Swatches panel, make sure the fill color is the foreground swatch rather than the stroke color. If it isn't, click the fill swatch to bring it forward. Next, click a color swatch on the Swatches panel or mix up a new color in the Color panel. The background of the image frame will change color to match that color--and so will the white areas of the photo because InDesign treats white in grayscale images as transparent. Thus, when you give the image frame a background color, it shines through the white in the image.
Note: If nothing happened in this step, your image probably isn't saved as a genuine grayscale mode TIFF, JPEG, or PNG. Bring the image back into Photoshop and check its mode on the Image->Mode menu and make the appropriate changes.
Add a second color. Now that your image is tinted with a single color, you don't have to stop there. You can go ahead and add a second color for a distinctive effect. To do that, switch to the Direct Selection tool (the white arrow) and click on the image inside the frame. You'll see the image bounding box go from blue (the layer color) to brown to indicate that you're editing the image itself, not the frame. Now, pick another fill color from the Swatches or Color panels. Whatever color you pick will replace the black and gray values--all shades except pure white.
Create a sepia tone. To achieve a sepia effect, start with a background (frame fill) CMYK color (from InDesign's Color panel) of C: 2, M: 8, Y: 33, K: 3, and a foreground (image) color of C: 35, M: 56, Y: 61, K: 53.
You might be wondering: If you must prep grayscale images in Photoshop, why not just do the tinting there, too? You could, but then you'd have to save the image in those colors. The above technique lets you simply save a single grayscale image while giving you the freedom to tint, adjust, and retint it as often as you like, with as many copies on the page as you like, all with only one linked image file to manage.
Pariah S. Burke is the author of Mastering InDesign CS3 for Print Design and Production (Sybex, 2007), and other books; a freelance graphic designer; and the publisher of the Web sites GurusUnleashed.com, WorkflowFreelance.com, and CreativesAre.com. Pariah lives in Portland, Ore.