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Part II &' Painting and Retouching148&' Diffusion Dither: Select this option from the Use pop-up menu to create amezzotint-like effect, as demonstrated in the second example in Figure 4-6.Again, because this option converts an image into thousands of stray pixels,you can expect your image to darken dramatically when output to a low-resolution laser printer and when reproduced.So be sure to lighten theimage with something like the Levels command (as described in Chapter 17)before selecting this option.Figure 4-6: The results of selecting the Pattern Dither option (top) and the muchmore acceptable Diffusion Dither option (bottom).&' Halftone Screen: When you select this option from the Use pop-up menu andpress Enter, Photoshop displays the dialog box shown in Figure 4-7.Theseoptions enable you to apply a dot pattern to the image, as demonstrated inFigure 4-8.Enter the number of dots per inch in the Frequency option box andthe angle of the dots in the Angle option box.Then select a dot shape from theShape pop-up menu.Figure 4-8 shows examples of four shapes, each with afrequency of 24 lines per inch. Chapter 4 &' Defining Colors149Figure 4-7: This dialog box appears when you select theHalftone Screen option in the Bitmap dialog box.Round DiamondLine CrossFigure 4-8: Four random examples of halftone cell shapes.In all cases, theFrequency value was set to 24. Part II &' Painting and Retouching150Cross-I cover screen patterns and frequency settings in more depth in the ChangingReferencethe halftone screen section of Chapter 18.&' Custom Pattern: If you ve defined a repeating pattern using Edit ª' DefinePattern, you can use it as a custom dither pattern.Figure 4-9 shows two cus-tom examples.I created the first pattern using the Twirl Pattern file, which isstored in the Displacement Maps folder in the Plug-Ins folder.I created thesecond pattern manually using the Add Noise, Emboss, and Ripple filters(as discussed in the Creating texture effects section of Chapter A on theCD-ROM for this book).Figure 4-9: Two examples of employing repeating patterns (created with Edit ª'Define Pattern) as custom halftoning patterns.Cross-For a complete guide to creating and defining patterns in Photoshop, see theReference Applying Repeating Patterns section of Chapter 7. Chapter 4 &' Defining Colors151To use a custom pattern, open the Custom Pattern palette in the Bitmap dia-66log box, as shown in Figure 4-5.Click the icon for the pattern you want to use.If you don t feel like creating your own patterns, use one of the preset patternsthat ship with Photoshop 6.A number of these patterns appear by default inthe palette; to access additional patterns, choose Load from the palette menu(click the right-pointing triangle in the upper-right corner of the palette to dis-play the menu).You can find the patterns in the Patterns folder, which livesinside the Presets folder.To delete a pattern from the palette, click its iconand choose Delete from the palette menu.CautionPhotoshop lets you edit individual pixels in the so-called bitmap mode, but that sabout the extent of it.After you go to black-and-white, you can neither perform anyserious editing nor expect to return to the grayscale mode and restore your originalpixels.So be sure to finish your image editing before choosing Image ª' Mode ª'Bitmap.Even more important, make certain to save your image before convertingit to black-and-white.Frankly, saving is a good idea prior to performing any colorconversion.Using Photoshop s Other Color SelectionMethodsIn addition to the Color Picker dialog box, Photoshop provides a handful of addi-tional techniques for selecting colors.The sections that finish out this chapterexplain how to use the Custom Colors dialog box, the Colors palette, and the eye-dropper tool.None of this information is terribly exciting, but it will enable you towork more efficiently and conveniently.Predefined colorsIf you click the Custom button inside the Color Picker dialog box, Photoshop dis-plays the Custom Colors dialog box shown in Figure 4-10.In this dialog box, youcan select from a variety of predefined colors by choosing the color family fromthe Book pop-up menu, moving the slider triangles up and down the color sliderto specify a general range of colors, and ultimately, selecting a color from the colorlist on the left.If you own the swatchbook for a color family, you can locate a spe-cific color by entering its number on the keyboard.The color families represented in the Book pop-up menu fall into seven brands:ANPA (now NAA, as I explain shortly), DIC, Focoltone, HKS, Pantone, Toyo, andTrumatch, all of which get a big kick out of capitalizing their names in dialog boxes.I honestly think one of these companies would stand out better if its name weren tcapitalized.Anyway, at the risk of offending a few of these companies, you re likelyto find certain brands more useful than others.The following sections briefly intro-duce the brands in order of their impact on the American market forgive me forbeing ethnocentric in this regard from smallest to greatest impact.Photoshop Part II &' Painting and Retouching152Figure 4-10: The Custom Colors dialog box enables you to select predefinedcolors from brand-name libraries.The color families represented in the Book pop-up menu fall into seven brands:ANPA (now NAA, as I explain shortly), DIC, Focoltone, HKS, Pantone, Toyo, andTrumatch, all of which get a big kick out of capitalizing their names in dialog boxes.I honestly think one of these companies would stand out better if its name weren tcapitalized.Anyway, at the risk of offending a few of these companies, you re likelyto find certain brands more useful than others.The following sections briefly intro-duce the brands in order of their impact on the American market forgive me forbeing ethnocentric in this regard from smallest to greatest impact.TipThe number-one use for predefined colors in Photoshop is in the creation of duo-tones, tritones, and quadtones (described in Chapter 18).You can also use prede-fined colors to match the colors in a logo or some other important element in animage to a commercial standard.And you can add an independent channel for apredefined color and print it to a separate plate, as discussed later in this chapter.Focoltone, DIC, Toyo, and HKSFocoltone, Dianippon Ink and Chemical (DIC), Toyo, and HKS fall into the negligibleimpact category.All are foreign color standards with followings abroad.Focoltoneis an English company; not English speaking (although they probably do), butEnglish living, as in commuting-to-France-through-the-Channel England.DIC andToyo are popular in the Japanese market, but have next to no subscribers outsideJapan.HKS formerly was provided only in the German and French versions ofPhotoshop, but enough people asked for it to be included in other languagesthat it now is available in all versions of the program. Chapter 4 &' Defining Colors153Newspaper Association of AmericaAmerican Newspaper Publishers Association (ANPA) recently changed its name toNAA, which stands for Newspaper Association of America, and updated its color cat-alog.NAA provides a small sampling of 45 process colors (mixes of cyan, magenta,yellow, and black ink) plus 5 spot colors (colors produced by printing a single ink).The idea behind the NAA colors is to isolate the color combinations that reproducemost successfully on inexpensive newsprint and to provide advertisers with a solidrange of colors from which to choose, without allowing the color choices to get outof hand.You can purchase a swatch book from NAA for $35
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