Photoshop 6 for Windows Bible- P29

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Photoshop 6 for Windows Bible- P29:If you are reading this foreword, it probably means that you’ve purchased a copy of Adobe Photoshop 6.0, and for that I and the rest of the Photoshop team at Adobe thank you. If you own a previous edition of the Photoshop Bible, you probably know what to expect. If not, then get ready for an interesting trip.

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Nội dung Text: Photoshop 6 for Windows Bible- P29

Chapter 18 ✦ Printing Images 813 Choosing a printer To select a printer, choose Start ➪ Settings ➪ Printers. Right-click your printer of choice and select Set As Default on the resulting pop-up menu, as shown in Figure 18-1. If you want to add a printer, double-click the Add Printer icon, and be sure to have either your Windows CD-ROM or a drivers disk from your printer manufacturer. Figure 18-1: Specify your default printer from inside the Printers window. Printer drivers help the PC hardware, Windows, and Photoshop translate the con- tents of an image to the printer hardware and the page-description language it uses. You generally want to select the driver for your specific model of printer. But you can, if necessary, prepare an image for output to a printer that isn’t currently hooked up to your computer. For example, you can use this technique prior to submitting a document to be output on an imagesetter at a service bureau. Most high-end Windows graphics applications can take advantage of PostScript printer description (PPD) files. A single driver can’t account for the myriad differ- ences between different models of PostScript printers, so each PPD serves as a lit- tle guidance file, customizing the driver to accommodate a specific printer model. Windows lets you attach a PPD file globally to your PostScript printer, for which you need both the PPD file and the INF file to tell Windows what to install. (Adobe offers its own printer driver called AdobePS — available via www.adobe.com — which doesn’t require INF files. The setup program works only for Adobe-licensed PostScript printers, however.)
814 Part V ✦ Color for Print and the Web Tip Windows also lets you switch printers from inside an application. Just choose File ➪ Page Setup (Ctrl+Shift+P) inside Photoshop and select the printer you want to use from the Name pop-up menu. Setting up the page Photoshop 6 The next step is to define the relationship between the current image and the page on which it prints. In Photoshop 6, you handle most aspects of this part of the print- ing process in the new Print Options dialog box, shown in Figure 18-2. To open the dialog box, choose File ➪ Print Options or press Ctrl+Alt+P. When you first open the dialog box, the options shown at the bottom half of the figure aren’t visible; select the More Options check box to display them. Figure 18-2: The new Print Options dialog box enables you to precisely position the image, scale the image, and handle almost all other print setup chores. The settings in the Print Options dialog box, however, relate to the printer, paper size, and page orientation you select in the Page Setup dialog box. So unless you want to use Page Setup options that you already established, click the Page Setup
Chapter 18 ✦ Printing Images 815 button to transport to that dialog box. Alternatively, you can open the dialog box by choosing File ➪ Page Setup or by pressing Ctrl+Shift+P when the Print Options dialog box isn’t open. The next section explains the important choices you need to make in the Page Setup dialog box; after that, I discuss a myriad of other print settings. Note Some of Photoshop’s print options may appear in several different dialog boxes. For example, you may find image scaling controls in the Page Setup dialog box, as well as in the Print Options dialog box. For most print attributes, Photoshop doesn’t care where you specify your print options. But if you want to scale the image for output, use the Scaled Print Size controls in the Print Options dialog box. If you scale the image in the Page Setup dialog box, the Scale, Height, and Width values in the Print Options dialog box may not reflect accurate values. The Page Setup dialog box The Page Setup dialog box varies depending on what kind of printer you use. I usu- ally show the Page Setup dialog box for a standard PostScript printer. But this time around, I reckoned a color ink-jet printer might be more in keeping with the current state of the art. Therefore, Figure 18-3 shows the Page Setup options for Epson’s Color Stylus 800. Figure 18-3: Use this dialog box to choose the printer, page size, and image orientation.
816 Part V ✦ Color for Print and the Web Even though the Page Setup dialog box offers different options for different print- ers, you should always have access to the following (or their equivalents): ✦ Paper size: Select the size of the paper loaded into your printer’s paper tray. The paper size you select determines the imageable area of a page — that is, the amount of the page that Photoshop can use to print the current image. For example, the Letter option calls for a page that measures 8.5 × 11 inches, but only about 7.5 × 10 inches is imageable. ✦ Source: Virtually all printers include paper cartridges, but some permit you to manually feed pages or switch between cartridges. Use this option to decide where your paper is coming from. ✦ Orientation: You can specify whether an image prints upright on a page (Por- trait) or on its side (Landscape) by selecting the corresponding Orientation icon. Use the Landscape setting when an image is wider than it is tall. Printer-specific options In addition to the options in the Page Setup dialog box, you may be able to control certain print attributes specific to the selected printer. To explore these options from inside the Page Setup dialog box, click the Properties button to display a multipaneled dialog box of additional choices. In the case of the Color Stylus 800, for example, clicking on the Properties button displays the dialog box shown in Figure 18-4. Here I can modify the print quality, select whether to print in black- and-white or color, and specify the type of paper I’m using. Figure 18-4: Click the Properties button to access still more settings that are specific to the kind of printer you’re using.
Chapter 18 ✦ Printing Images 817 Position and scaling options All of the options I’ve described so far are constant regardless of what application you’re using. However, the settings inside the Print Options dialog box (shown ear- lier, in Figure 18-2) are unique to Photoshop. Photoshop 6 The top half of the dialog box includes controls that are new to Photoshop 6. These welcome additions enable you to position the image on the page and perform a few other handy printing adjustments: ✦ Position: Enter values into the Top and Left option boxes to position the image with respect to the top-left corner of the page. You can select from four different measurement units for these options. If you want the image to print smack dab in the middle of the page, as it did in previous versions of Photoshop, select the Center Image check box. And if you’re not overly concerned about placing the image exactly at a certain spot, deselect the Center Image check box and then just drag the image in the preview on the left side of the dialog box. The preview updates to show you the current image position. In the preview, the white area represents the printable region of the paper; shadowed areas indicate the margins required by the selected printer. ✦ Scaling: If you want to adjust the image size for the current print job only, use these controls. They have no affect on the actual image file — they merely scale the image for printing. You can enter a scale percentage; anything over 100 percent enlarges the image, and values under 100 percent reduce the image. Or enter a specific size in the Height and Width option boxes. If you want Photoshop to adjust the image automatically to fit the page size, select the Scale to Fit Media check box. The Show Bounding Box option, when selected, displays handles at the cor- ners of the preview image. For quick and dirty scaling, you can drag the han- dles until the image is the approximate print size you want. ✦ Print selection: If you selected a rectangular area before opening the dialog box, you can print just the selection by turning on the Print Selected Area check box. Any scaling and position settings still apply to the printed output. Tip Photoshop prints only visible layers and channels, so you can print select layers or channels in an image by hiding all the other layers or channels. (To hide and display layers and channels, click the eyeball icon next to the layer or channel name in the Layers or Channels palette, respectively.) To print a single layer or channel, Alt-click the eyeball. Output options Photoshop 6 To display the special print options shown at the bottom of Figure 18-2, earlier in this chapter, select the Show More Options check box and then select Output from the pop-up menu immediately below. (If any options are dimmed, your printer doesn’t support them.)
818 Part V ✦ Color for Print and the Web The five Output buttons work as follows: ✦ Background: To assign a color to the area around the printed image, click this button and select a color from the Color Picker dialog box, described in Chapter 4. This button and the one that follows (Border) are designed specifi- cally to accommodate slides printed from a film recorder. If you select either of these options, Photoshop updates the preview to show them. ✦ Border: To print a border around the current image, click this button and enter the thickness of the border into the Width option box. The border auto- matically appears in black. ✦ Bleed: This button lets you print outside the imageable area of the page when outputting to an imagesetter. (Imagesetters print to huge rolls of paper or film, so you can print far outside the confines of standard page sizes. Most other printers use regular old sheets of paper; any bleed — were the printer to acknowledge it — would print off the edge of the page.) Click the Bleed button and enter the thickness of the bleed into the Width option box. Two picas (24 points) is generally a good bet. (Bleeds are defined in the “Understanding Printing Terminology” glossary at the beginning of this chapter.) ✦ Screen: Click this button to enter a dialog box that enables you to change the size, angle, and shape of the printed halftone cells, as described in the upcom- ing “Changing the halftone screen” section. ✦ Transfer: The dialog box that appears when you click this button enables you to redistribute shades in the printed image, as explained in the upcoming sec- tion, “Specifying a transfer function.” Most of the Output check boxes — all except Negative, Emulsion Down, Interpolation, and Include Vector Data — append special labels and printer marks to the printed ver- sion of the image. Figure 18-5 illustrates how they look when printed. For all options except Interpolation and Include Vector Data, Photoshop shows the result of select- ing the check box in the image preview. ✦ Interpolation: If you own an output device equipped with PostScript Level 2 or later, you can instruct Photoshop to antialias the printed appearance of a low-resolution image by selecting this option. The output device resamples the image up to 200 percent and then reduces the image to its original size using bicubic interpolation (as described in the “General preferences” section of Chapter 2), thereby creating a less-jagged image. This option has no effect on older-model PostScript devices. ✦ Calibration Bars: A calibration bar is a 10-step grayscale gradation beginning at 10 percent black and ending at 100 percent black. The function of the cali- bration bar is to ensure all shades are distinct and on target. If not, the output device isn’t properly calibrated, which is a fancy way of saying the printer’s colors are out of whack and need realignment by a trained professional armed with a hammer and hacksaw. When you print color separations, the Calibration Bars check box instructs Photoshop to print a gradient tint bar and progressive color bar, also useful to printing professionals.
Chapter 18 ✦ Printing Images 819 Label Corner crop marks Cranky kiddo.tiff Modern youngster Calibration bar Center crop marks Registration marks Hey, don’t mess with me, man. I’m grumpy ’cause Caption I can’t change the font for this caption. Aargh! Figure 18-5: An image printed with nearly all the Output check boxes turned on. ✦ Registration Marks: Select this option to print eight crosshairs and two star targets near the four corners of the image. Registration marks are imperative when you print color separations; they provide the only reliable means to ensure exact registration of the cyan, magenta, yellow, and black printing plates. When printing a composite image, however, you can ignore this option. ✦ Corner Crop Marks: Select this option to print eight hairline crop marks — two in each of the image’s four corners — which indicate how to trim the image in case you anticipate engaging in a little traditional paste-up work.
820 Part V ✦ Color for Print and the Web ✦ Center Crop Marks: Select this option to print four pairs of hairlines that mark the center of the image. Each pair forms a cross. Two pairs are located on the sides of the image, the third pair is above it, and the fourth pair is below the image. ✦ Caption: To print a caption beneath the image, select this option. Then press Enter to exit this dialog box, choose File ➪ File Info, and enter a caption into the File Info dialog box. The caption prints in 9-point Helvetica. This is strictly an image-annotation feature, something to help you 17 years down the road, when your brain starts to deteriorate and you can’t remember why you printed the darn thing. (You might also use the caption to keep images straight in a busy office where hundreds of folks have access to the same images, but I don’t like this alternative as much because I can’t make fun of it.) ✦ Labels: When you select this check box, Photoshop prints the name of the image and the name of the printed color channel in 9-point Helvetica. If you process many images, you’ll find this option extremely useful for associating printouts with documents on disk. Note Incidentally, Figure 18-5 shows the actual labels and marks exactly as they print. I started by printing the Photoshop image to disk as an EPS (Encapsulated PostScript) file (as I describe later in the “Printing pages” section). Then I used Illustrator to open the EPS file and assign the callouts. This may not sound like much, but in the old days this would have been impossible. Figure 18-5 repre- sents a practical benefit to Illustrator’s (and Photoshop’s) ability to open just about any EPS file on the planet. ✦ Emulsion Down: The emulsion is the side of a piece of film on which an image is printed. When the Emulsion Down check box is turned off, film prints from an imagesetter emulsion side up; when the check box is turned on, Photoshop flips the image so the emulsion side is down. Like the Negative option, dis- cussed next, this option is useful only when you print film from an imageset- ter, and this option should be set in accordance with the preferences of your commercial printer. ✦ Negative: When you select this option, Photoshop prints all blacks as white and all whites as black. In-between colors switch accordingly. For example, 20 percent black becomes 80 percent black. Imagesetter operators use this option to print composites and color separations to film negatives. Photoshop ✦ Include Vector Data: If your image contains any vector objects or type for 6 which outline data is available (not outline or protected fonts), select this check box to send the actual vector data to a PostScript printer. Your vector objects then can be scaled to any size without degrading in quality. Including the vector data increases the image file size, which can slow printing and cause other printing problems. But if you turn off the check box, everything in the image is sent to the printer as raster data. This reduces the file size, but you no longer can scale the vector objects or type with impunity. They’re subject to the same quality loss that occurs when you enlarge any pixel-based image.
Photoshop Chapter 18 ✦ Printing Images 821 ✦ Encoding: Select an option from this pop-up menu to control the encoding 6 method used to send the image file to the printer. In normal printing situa- tions, leave the option set to the default, Binary. If your network doesn’t sup- port binary encoding (highly unlikely in this day and age) or your printer is attached through the local parallel printer port, instead of the network, select the ASCII option to transfer PostScript data in the text-only format. The print- ing process takes much longer to complete, but at least it’s possible. If your printer supports PostScript Level 2 or later, you can also choose to use JPEG compression to reduce the amount of data sent to the printer. (This option is applicable to PostScript printers only.) Color management options Photoshop 6 After you select the Show More Options check box in the Print Options dialog box, you can display color-management settings by selecting Color Management from the pop-up menu, as shown in Figure 18-6. These options enable you to convert the image color space for printing only. You may want to do this to print a proof of the image on a printer other than the printer you’ll use for final output. To convert the color space of the actual image file, you need to use the techniques discussed in Chapter 16. Figure 18-6: Use these options to dictate which color-management settings you want Photoshop to use when printing. You can select from two Source Space options, Document and Proof. These options tell Photoshop whether you want to print the image according to the color profile officially assigned to the image file or according to the Proof Setup profile (the so- called “soft proofing” profile). Document uses the actual color profile; Proof uses the profile currently selected in the View ➪ Proof Setup submenu. The Profile options control whether Photoshop converts the image to a different profile during the print process. If you select Same As Source from the Profile pop- up menu, no conversion occurs. To convert to a different profile, select the profile
822 Part V ✦ Color for Print and the Web from the pop-up menu. You can then specify the rendering method by selecting it from the Intent pop-up menu. You can convert to any color space offered by either Photoshop or Kodak’s ICC CMS. Ideally, you want to select the specific profile for your brand of printer. If you can’t find such a profile, you’ll probably want to stick with the RGB Color space (specified with Edit ➪ Color Settings in Photoshop 6). Another option is to choose Working CMYK, which prints the image just as if you had converted it to the CMYK color space. Unfortunately, most consumer printers are designed to accommodate RGB images and fare pretty badly when printing artwork converted to CMYK. (This is precisely the reason I frequently select RGB Color even when printing a CMYK image — it flat out produces better results.) Tip If you own a color printer, I encourage you to take an hour out of your day and con- duct a few tests with the other Print Space options. For example, if you select Apple RGB, your printed image will darken several shades. This might throw you. Because the Apple RGB profile features the lightest of the monitor gammas — 1.8 — you might expect the image to print lighter. But what Photoshop is really doing is con- verting the colors as if the printer were as naturally light as an Apple RGB monitor. In order to maintain consistent color, the conversion therefore darkens the image to account for this unusually light device. Select the Wide Gamut setting and the colors appears lighter and washed out, again accounting for this hyper-saturated Space setting. So think opposite. Caution Yet another alternative is to convert an RGB image to the grayscale color space during printing. But it’s generally a bad alternative. Asking Photoshop to convert colors on the fly dramatically increases the output time, as well as the likelihood of printing errors. It’s better and much faster to simply convert the image to the grayscale mode (Image ➪ Mode ➪ Grayscale) and then print it. Cross- Again, if you’re unfamiliar with any of these terms or just don’t know which options Reference are best for your printing situation, review Chapter 16, where I discuss color man- agement in detail. Changing the halftone screen Before I explain this option, available when you select Output from the pop-up menu in the Print Options dialog box, I need to explain a bit more about how print- ing works. To keep costs down, commercial printers use as few inks as possible to create the appearance of a wide variety of colors. Suppose you want to print an image of a pink flamingo wearing a red bow tie. Your commercial printer could print the flamingo in one pass using pink ink, let that color dry, and then load the red ink and print the bow tie. But why go to all this trouble? After all, pink is only a lighter shade of red. Why not imitate the pink by lightening the red ink?
Chapter 18 ✦ Printing Images 823 Unfortunately, with the exception of dye-sublimation printers, high-end ink jets, and film recorders, output devices can’t print lighter shades of colors. They recognize only solid ink and the absence of ink. So how do you print the lighter shade of red necessary to represent pink? The answer is halftoning. The output device organizes printer pixels into spots called halftone cells. Because the cells are so small, your eyes cannot quite focus on them. Instead, the cells appear to blend with the white background of the page to create a lighter shade of an ink. Figure 18-7 shows a detail of an image enlarged to display the individual halftone cells. Figure 18-7: A detail from an image (left) is enlarged so that you can see the individual halftone cells (right). The cells grow and shrink to emulate different shades of color. Large cells result in dark shades; small cells result in light shades. Cell size is measured in printer pix- els. The maximum size of any cell is a function of the number of cells in an inch, called the screen frequency. For example, suppose the default frequency of your printer is 60 halftone cells per linear inch and the resolution is 300 printer pixels per linear inch. Each halftone cell must, therefore, measure 5 pixels wide by 5 pixels tall (300 ÷ 60 = 5), for a total of 25 pixels per cell (52 ). When all pixels in a cell are turned off, the cell appears white; when all pixels are turned on, you get solid ink. By turning on different num- bers of pixels — from 0 up to 25 — the printer can create a total of 26 shades, as demonstrated in Figure 18-8.
824 Part V ✦ Color for Print and the Web Figure 18-8: 5 × 5-pixel halftone cells with different numbers of pixels activated, ranging from 25 (top left) to 0 (bottom right). Each cell represents a unique shade from 100 to 0 percent black. Photoshop enables you to change the size, angle, and shape of the individual halftone cells used to represent an image on the printed page. To do so, click the Screen button in the Print Options dialog box (after clicking Show More Options and choosing Output from the pop-up menu). The Halftone Screens dialog box shown in Figure 18-9 appears. Figure 18-9: Use the Halftone Screens dialog box to edit the size, angle, and shape of the halftone cells for any one ink.
Chapter 18 ✦ Printing Images 825 In the dialog box, you can manipulate the following options: ✦ Use Printer’s Default Screens: Select this check box to accept the default size, angle, and shape settings built into your printer’s ROM. All other options in the Halftone Screens dialog box automatically become dimmed to show they are no longer in force. ✦ Ink: If the current image is in color, you can select the specific ink you want to adjust from the Ink pop-up menu. When you work with a grayscale image, no pop-up menu is available. ✦ Frequency: Enter a new value into this option box to change the number of halftone cells that print per linear inch. A higher value translates to a larger quantity of smaller cells; a smaller value creates fewer, larger cells. Frequency is traditionally measured in lines-per-inch, or lpi (as in lines of halftone cells), but you can change the measurement to lines per centimeter by selecting Lines/cm from the pop-up menu to the right of the option box. Tip Higher screen frequencies result in smoother-looking printouts. Raising the Frequency value, however, also decreases the number of shades an output device can print because it decreases the size of each halftone cell and, like- wise, decreases the number of printer pixels per cell. Fewer printer pixels mean fewer shades. You can calculate the precise number of printable shades using the following formula: Number of shades = (printer resolution ÷ frequency) 2 + 1 ✦ Angle: To change the orientation of the lines of halftone cells, enter a new value into the Angle option box. In the name of accuracy, Photoshop accepts any value between negative and positive 180 degrees. Caution When printing color composites to ink-jet and thermal-wax printers, and when printing color separations, Photoshop calculates the optimum Frequency and Angle values required to print seamless colors. In such a case, you should change these values only if you know exactly what you’re doing. Otherwise, your printout may exhibit weird patterning effects. When printing grayscale images, though, you can edit these values to your heart’s content. ✦ Shape: By default, most PostScript printers rely on roundish halftone cells. You can change the appearance of all cells for an ink by selecting one of six alter- nate shapes from the Shape pop-up menu. For a demonstration of four of these shapes, see Figure 4-8 in the “Black and white (bitmap)” section of Chapter 4. If you know how to write PostScript code, you can select the Custom option to display a text-entry dialog box and code away. ✦ Use Accurate Screens: If your output device is equipped with PostScript Level 2 or later, select this option to subscribe to the updated screen angles for full- color output. Otherwise, don’t worry about this option.
826 Part V ✦ Color for Print and the Web ✦ Use Same Shape for All Inks: Select this option if you want to apply a single set of size, angle, and shape options to the halftone cells for all inks used to represent the current image. Unless you want to create some sort of special effect, leave this check box deselected. The option is unavailable when you are printing a grayscale image. ✦ Auto: Click this button to display the Auto Screens dialog box, which automates the halftone editing process. Enter the resolution of your output device in the Printer option box. Then enter the screen frequency you want to use in the Screen option box. After you press Enter to confirm your change, Photoshop automatically calculates the optimum screen frequencies for all inks. This tech- nique is most useful when you print full-color images — because Photoshop does the work for you, you can’t make a mess of things. ✦ Load/Save: You can load and save settings to disk in case you want to reapply the options to other images. These buttons are useful if you find a magic com- bination of halftone settings that results in a really spectacular printout. Tip You can change the default size, angle, and shape settings Photoshop applies to all future images by Alt-clicking on the Save button. When you press Alt, the Save button changes to read ->Default. To restore the default screen settings at any time, Alt-click the Load button (
Chapter 18 ✦ Printing Images 827 years or so — I know it’s going to die one day but, until then, it keeps chugging along — I’ve discovered all gray values print overly dark. Dark values fill in and become black; light values appear a dismal gray, muddying up any highlights. The problem increases if I try to reproduce the image on a photocopier. To compensate for this overdarkening effect, I click the Transfer button in the Print Options dialog box after clicking Show More Options and choosing Output from the pop-up menu, and then I enter the values shown in Figure 18-10. Notice I lighten 20 percent on screen grays to 10 percent printer grays. I also lighten 90 percent screen grays to 80 percent printer grays. The result is a smooth, continuous curve that maps each gray value in an image to a lighter value on paper. Figure 18-10: The transfer function curve enables you to map on screen brightness values to specific shades on paper. The options in the Transfer Functions dialog box work as follows: ✦ Transfer graph: The transfer graph is where you map on-screen brightness values to their printed equivalents. The horizontal axis of the graph repre- sents on-screen brightness values; the vertical axis represents printed shades. The transfer curve charts the relationship between on screen and printed col- ors. The lower-left corner is the origin of the graph — the point at which both on-screen brightness value and printed shade are white. Move to the right in the graph for darker on-screen values; move up for darker printed shades. Click in the graph to add points to the line. Drag up on a point to darken the output; drag down to lighten the output. Cross- For a more comprehensive explanation of how to graph colors on a curve, Reference read about the incredibly powerful Curves command, covered in Chapter 17.
828 Part V ✦ Color for Print and the Web ✦ Percentage option boxes: The option boxes are labeled according to the on- screen brightness values. To lighten or darken the printed brightness values, enter higher or lower percentage values in the option boxes. There is a direct correlation between changes made to the transfer graph and the option boxes. For example, if you enter a value in the 50 percent option box, a new point appears along the middle line of the graph. ✦ Override Printer’s Default Functions: As an effect of printer calibration, some printers have custom transfer functions built into their read-only memory (ROM). If you have problems making your settings take effect, select this check box to instruct Photoshop to apply the transfer function you specify, regardless of the output device’s built-in transfer function. ✦ Load/Save: Use these buttons to load and save settings to disk. Alt-click the buttons to retrieve and save default settings. ✦ Ink controls: When you print a full-color image, five options appear in the lower-right corner of the Transfer Functions dialog box. These options enable you to apply different transfer functions to different inks. Select the All Same check box to apply a single transfer function to all inks. To apply a different function to each ink, deselect the check box, and then select one of the radio buttons and edit the points in the transfer graph as desired. Printing pages When you finish slogging your way through the Page Setup and Print Options dialog boxes, you can initiate the printing process by clicking the Print button in the Print Options dialog box or choosing File ➪ Print (Ctrl+P). The Print dialog box appears, shown in its RGB and CMYK forms in Figure 18-11. Photoshop 6 Several options in this dialog box also appear in the Print Options dialog box or the Page Setup dialog box, both discussed earlier in this chapter. The few remaining options you need to understand work as follows: ✦ Copies: Enter the number of copies you want to print in this option box. You can print up to 999 copies of a single image, although why you would want to do so is beyond me. ✦ Print Range: No such thing as a multipage document exists in Photoshop, so you can ignore these options for the most part. If you selected an image area with the rectangular marquee tool, you can print just the selected area by choosing the Selection radio button or by turning on the Print Selected Area check box in the Print Options dialog box. You may want to use this option to divide an image into pieces when it’s too large to fit on a single page.
Chapter 18 ✦ Printing Images 829 Figure 18-11: The Print dialog box as it appears when printing a color image. ✦ Print to File: Exclusively applicable to PostScript printing, this option lets you save a PostScript-language version of the file on disk rather than printing it directly to your printer. Deselect the option to print the image to an output device as usual. Select Print to File to write a PostScript-language version of the image to disk. Tip Because Photoshop offers its own EPS option via the Save dialog box, you’ll probably want to ignore this option. In fact, the only reason to select Print to File is to capture printer’s marks, as I did back in Figure 18-5. If you do, a sec- ond dialog box appears, asking where you want to save the PostScript file. You can navigate just as in the Open and Save dialog boxes. For the best results, select the Binary radio button. ✦ Setup: This button takes you to the Page Setup dialog box, discussed previously.
830 Part V ✦ Color for Print and the Web Press Enter inside the Print dialog box to start the printing process on its merry way. To cancel a print in progress, click the Cancel button. If you neglect to cancel before Photoshop spools the print job, don’t worry, you can still cancel. Choose Settings ➪ Printers from the Windows Start menu to display the Printers dialog box. Right-click the icon for the printer you’re using and then select Open. Or you can double-click that tiny printer icon that appears on the far-right side of the taskbar. Either way, Windows shows you a window listing the current print jobs in progress. You can pause or cancel the selected print job by choosing a command from the Document menu. Creating Color Separations It’s rare that you’ll ever have to print color separations directly from Photoshop. You’ll more likely import the image into QuarkXPress, PageMaker, InDesign, or a similar application before printing separations. It’s even more likely that you’ll take the image or page-layout file to a commercial printer and have a qualified techni- cian take care of it. So why discuss this process? Two reasons. First, it’s always a good idea to at least peripherally understand all phases of the computer imaging process, even if you have no intention of becoming directly involved. This way, if something goes wrong on the printer’s end, you can decipher the crux of the problem and either propose a solution or strike a compromise that still works in your favor. Second, before you import your image into another program or submit it to a com- mercial printer, you’ll want to convert the RGB image to the CMYK color space. (You don’t absolutely have to do this — with Photoshop’s improved color matching functions, you can exchange RGB images with greater confidence — but it’s always a good idea to prepare your images down to the last detail, and CMYK is invariably the final destination for printed imagery.) Outputting separations Accurately converting to CMYK is the trickiest part of printing color separations; the other steps require barely any effort at all. So without further ado, here’s how you convert an image to the CMYK color space and print separations. Many of the steps are the same as when printing a grayscale or color composite, others are new and different. STEPS: Printing CMYK Color Separations 1. Calibrate your monitor and specify the desired RGB environment. Use the techniques discussed in the “The Gamma control panel” and “Selecting the ideal working space” sections of Chapter 16.
Chapter 18 ✦ Printing Images 831 2. Identify the final output device. Again, follow the advice I give in Chapter 16, this time, in the section “Custom CMYK Setup.” If you’re lucky, your commer- cial printer may provide a CMYK table that you can load. Otherwise, you’ll have to grapple with some weird settings. The good news is that you only need to complete this step once for each time you switch hardware. If you always use the same commercial printer, you can set it up and forget about it. 3. Convert the image to the CMYK color space. Choose Image ➪ Mode ➪ CMYK Color to convert the image from its present color mode to CMYK. 4. Adjust the individual color channels. Switching color modes can dramati- cally affect the colors in an image. To compensate for color and focus loss, you can edit the individual color channels as described in the “Color Channel Effects” section of Chapter 4. 5. Trap your image, if necessary. If your image features many high-contrast ele- ments and you’re concerned your printer might not do the best job of register- ing the cyan, magenta, yellow, and black color plates, you can apply Image ➪ Trap to prevent your final printout from looking like the color funnies. (When working with typical “continuous-tone” photographs, you can skip this step.) 6. Choose your printer. Select the printer you want to use, as described earlier in this chapter in the “Choosing a printer” section. Photoshop 7. Turn on a few essential printer marks. Choose File ➪ Page Setup (Ctrl+Shift+P) 6 to specify the size of the pages and the size and orientation of the image on the pages, as described in “The Page Setup dialog box” section earlier in this chap- ter. And in the Print Options dialog box, also introduced earlier, be sure to select the Calibration Bars, Registration Marks, and Labels check boxes, at the very least. (You need to select the Show More Options check box and then select Output from the pop-up menu to display these options.) 8. Adjust the halftone and transfer functions as needed. Click the Screen and Transfer buttons in the Print Options dialog box to modify the halftone screen dots and map brightness values for each of the CMYK color channels, as described earlier in the “Changing the halftone screen” and “Specifying a transfer function” sections. This step is entirely optional. Photoshop 6 9. Send the job to the printer. You can click the Print button in the Print Options dialog box or, if the dialog box isn’t open, choose File ➪ Print (Ctrl+P). Then choose Separations from the Profile pop-up menu in the Print Space section of the dialog box. This tells Photoshop to print each color channel to a separate piece of paper or film. Note You also can create color separations by importing an image into a page-layout or drawing program. Instead of choosing your printer in Step 6, save the image in the DCS format, as described in the “QuarkXPress DCS” section of Chapter 3. Steps 6 through 9 are repeats of concepts explained in previous sections of this chap- ter. Steps 1, 3, and 4 were covered at length in Chapters 4 and 16. This leaves Steps 2 and 5 — CMYK Setup and trapping — which I explain in the following sections.
832 Part V ✦ Color for Print and the Web Color trapping If color separations misalign slightly during the reproduction process (a problem called misregistration), the final image can exhibit slight gaps between colors. Suppose an image features a 100 percent cyan chicken against a 100 percent magenta background. (Pretty attractive image idea, huh? Go ahead, you can use it if you like.) If the cyan and magenta plates don’t line up exactly, you’re left with a chicken with a white halo around it. Yuck. A trap is a little extra bit of color that fills in the gap. For example, if you choose Image ➪ Trap and enter 4 into the Width option box, Photoshop outlines the chicken with an extra 4 pixels of cyan and the background with an extra 4 pixels of magenta. Now the registration can be off a full 8 pixels without any halo occurring. Continuous-tone images, such as photographs and natural-media painting, don’t need trapping because no harsh color transitions occur. In fact, trapping actually harms such images by thickening up the borders and edges, smudging detail, and generally dulling the focus. One of the primary reasons to use the Trap command, therefore, is to trap raster- ized drawings from Illustrator or FreeHand. Some state-of-the-art prepress systems trap documents by first rasterizing them to pixels and then modifying the pixels. Together, Photoshop and Illustrator (or FreeHand) constitute a more rudimentary but, nonetheless, functional trapping system. When you open an illustration in Photoshop, the program converts it into an image according to your size and reso- lution specifications, as described in the “Rasterizing an Illustrator or FreeHand file” section of Chapter 3. Once the illustration is rasterized, you can apply Image ➪ Trap to the image as a whole. Despite the command’s simplicity, it handles nearly all trapping scenarios, even going so far as to reduce the width of the trap incre- mentally as the colors of neighboring areas grow more similar. Caution If you plan on having a service bureau trap your files for you, do not apply Photo- shop’s Trap command. You don’t want to see what happens when someone traps an image that’s already been trapped. If you’re paying the extra bucks for profes- sional trapping, leave it to the pros. Printing Duotones It’s been a few pages since the “Understanding Printing Terminology” section, so here’s a quick recap: A duotone is a grayscale image printed with two inks. This technique expands the depth of the image by allowing additional shades for high- lights, shadows, and midtones. If you’ve seen a glossy magazine ad for perfume, designer clothing, a car, or just about any other overpriced commodity, you’ve seen a duotone. Words like rich, luxurious, and palpable come to mind.