Adobe 23101335 User Guide - Page 389

ADOBE PHOTOSHOP 6.0 379 User Guide dot gain using the settings in the CMYK Setup dialog box. Transfer functions are useful, however, when compensating for a poorly calibrated output device. For more information, see "Compensating for dot gain in film using transfer functions" in online Help. Interpolation Reduces the jagged appearance of a low-resolution image by automatically resampling up while printing. However, resampling may reduce the sharpness of the image quality. (See "About resampling" on page 96.) Some PostScript Level 2 (or higher) printers have interpolation capability. If your printer doesn't, this option has no effect. Calibration Bars Prints an 11-step grayscale, a transition in density from 0 to 100% in 10% increments. With a CMYK color separation, a gradient tint bar is printed to the left of each CMY plate, and a progressive color bar to the right. Note: Calibration bars, registration marks, crop marks, and labels will print only if the paper size is larger than the printed image dimensions. Registration Marks Prints registration marks on the image (including bull's-eyes and star targets). These marks are used primarily for aligning color separations. Crop Marks Prints crop marks where the page is to be trimmed. You can print crop marks at the corners, at the center of each edge, or both. Labels Prints the filename above the image. Caption Prints any caption text entered in the File Info dialog box. (See "Adding file information (Photoshop)" on page 366.) Caption text always prints as 9-point Helvetica plain type. Negative Prints an inverted version of the image. Unlike the Invert command in the Image menu, the Negative option converts the output, not the on-screen image, to a negative. If you print separations directly to film, you probably want a negative, although in many countries film positives are common. Check with your print shop to determine which is required. Emulsion Down Makes type readable when the emulsion is down-that is, when the photosensitive layer on a piece of film or photographic paper is facing away from you. Normally, images printed on paper are printed with emulsion up, with type readable when the photosensitive layer faces you. Images printed on film are often printed with emulsion down. To determine the emulsion side, examine the film under a bright light after it has been developed. The dull side is the emulsion; the shiny side is the base. Check whether your print shop requires film with positive emulsion up, negative emulsion up, positive emulsion down, or negative emulsion down. Selecting halftone screen attributes Halftone screen attributes include the screen frequency and dot shape for each screen used in the printing process. For color separations, you must also specify an angle for each of the color