href="#fb3_img_img_22112777-25eb-542b-8863-ee9fef737378.png" alt="Photo depicts Grayscale supporting 256 shades of gray."/>
FIGURE 2-3: Grayscale supports 256 shades of gray.
When you choose Image ⇒ Mode ⇒ Grayscale to convert to Grayscale mode, a warning message asks you to confirm that you want to discard all color information. If you don’t want to see this warning every time you convert an image to grayscale, select the option not to show the dialog box again before you click Discard.
Duotone
Use Duotone mode when you’re creating a one to four-color image created from spot colors (solid ink, such as Pantone colors). You can also use Duotone mode to create monotones, tritones, and quadtones. If you’re producing a two-color job, duotones create a beautiful alternative to full color.
To create a duotone, follow these steps:
1 Choose Image ⇒ Mode ⇒ Grayscale.
2 Choose Image ⇒ Mode ⇒ Duotone.
3 In the Duotone dialog box, select Duotone from the Type drop-down list.Your choices range from monotone (one-color) up to quadtone (four-color). Black is assigned automatically as the first ink, but you can change it, if you like.
4 To assign a second ink color, click the white swatch immediately under the black swatch.The Color Picker appears, as shown in Figure 2-4.FIGURE 2-4: Click the white swatch to open the Color Picker dialog box and then click on Color Libraries.
5 Click the Color Libraries button, and then select Pantone Solid Coated as the library, it should be set by default.
6 Now comes the fun part: Type (quickly!) the Pantone or PMS number you want to access, and then click OK. (See Figure 2-5.) If you type too slowly, the incorrect number will appear.There’s no text field for you to enter the number, so don’t look for one. Just type the number while the Color Libraries dialog box is open.Try entering 300 to select PMS 300. You can already see that you’ve created a tone curve.
7 Click the Curve button to the left of the ink color to further tweak the colors.
8 Click and drag the curve to adjust the black in the shadow areas, perhaps to bring down the color overall. Then experiment with the results.FIGURE 2-5: In the Color Library dialog box, type a Pantone number in quickly, for instance 3-0-0 for PMS 300; there is no text field.
9 (Optional) If you like your duotone settings, store them by clicking the small Preset Options button to the right of the Preset drop-down list, as shown in Figure 2-6. Type a name into the Name text box, browse to a location on your computer, and then click Save. You can also use one of the presets that Adobe provides. Do this by selecting an option from the Presets drop-down menu at the top of the Duotone dialog box.Click the Preset Options button to find your saved presets.Duotone images must be saved in the Photoshop Encapsulated PostScript (EPS) format in order to support the spot colors. If you choose another format, you risk the possibility of converting colors into a build of CMYK (Cyan, Magenta, Yellow, and Black).
10 Click OK when you’re finished.
FIGURE 2-6: Save your duotone by clicking the Preset Options button.
Index color
Typically you don’t edit your images in the Index color mode, but you probably have saved a file in this mode. If you have ever saved a GIF file out of Photoshop, you have experienced working with Indexed color firsthand. Indexed Color mode (see Figure 2-7) uses a color lookup table (CLUT) to create the image from a limited palette of colors. In this example, the flower was set to reduce to 10 colors.
FIGURE 2-7: Index color uses a limited number of colors to create an image.
A CLUT contains all colors that make up an image, like a box of crayons used to create artwork. If you have a box of only eight crayons that are used to color an image, you have a CLUT of only eight colors. Of course, your image would look much better if you used the 64-count box of crayons with the sharpener on the back, but those additional colors also increase the size of the CLUT and the file size.
The highest number of colors that can be in Indexed Color mode is 256. When saving web images, you often have to define a color table in order to keep a file size small. We discuss saving files for the web in Chapter 10 of this minibook.
RGB
RGB (Red, Green, Blue) mode, shown in Figure 2-8, is the standard format you work in if you import images from a digital camera or import images from a copier or scanner. For complete access to Photoshop’s features, RGB is the best color mode to work in. If you’re working on images for use on the web, color copiers, desktop color printers, or onscreen presentations, stay in RGB mode.
FIGURE 2-8: RGB creates the image from red, green, and blue.
CMYK
