The saying in IT computing “Garbage in, Garbage out” also applies to printing. We recommend that you start creating your artwork with the best possible image source. The better the original, the more latitude the printer has in achieving the results you want. Use photographs that exhibit the
full tonal range. Don’t convert a color photo to make a black-and-white reproduction, if a black-and-white original is available. Start with the best you can get because each step results in a generational loss in quality.
Prepare your art in the program that is best-suited for
the task. Illustrator® is a drawing (vector) program, ideal for logos, packaging, posters and single-page layouts. Photoshop® is a pixel-based (raster) program that lets you size, color-correct and manipulate scanned images such as photographs and flat art. Neither is intended for multi-page documents. For that, use a page layout program such as QuarkXPress® or InDesign®.
Scale, rotate, flip and manipulate images in the original graphic application (Photoshop® or Illustrator®) before importing them into your page-layout program (QuarkXPress® or InDesign®). If done in a page layout program, these steps consume a lot of computer memory and may cause
Photoshop® provides tremendous pixel control, but keep in mind that raster software cannot enlarge images without
a loss in quality. When producing a digital image, start big because you can scale down with impunity. If you need to make an image larger, it is best to rescan or reshoot it at a higher resolution.
If you are doing color corrections or manipulations on your own, rely on the numerical color gauges in Photoshop® rather than what you see on the screen. Be sure to color calibrate your monitor and printer to reduce discrepancies.
Build your files at actual size unless your final size is too large for your software to accommodate. A printed piece with a final size of 8.5 x 11 should be built to 8.5 x 11 page size. Spreads should be created as two 8.5 x 11 pages, not as a single 17 x 11 form. Before releasing, add 1/8th inch bleeds where appropriate and be sure to indicate this. Let your printer make any adjustments for crossovers, gutter grind-off, creep, etc.
Remember that offset printing requires that all files be
in CMYK to separate properly. For stock images that are usually supplied in RGB mode, printers often prefer to make the conversions themselves. If the printer requests otherwise, ask for a conversion profile to follow. Keep in mind that standard default settings on your software may convert some colors to straight black, rather than build the color out of CMYK. Images, especially with flesh tones, may appear dark and muddy.