Before sending a print piece for production, it’s a good idea to proof the colors using the tools provided in Photoshop, Illustrator, and Indesign. Both Indesign and Illustrator have an “overprint preview” and a “proof colors” preview. Photoshop has a “proof colors” preview and CMYK channels that allow each plate to be studied separately. In photoshop, using the channels to proof comes in very handy to more easily see things like banding, which is a big concern in large scale graphics, but can also affect the quality of smaller print items. Banding is both less of an issue than it used to be, since photoshop and printers have become more sophisticated, and more of an issue than before, since photoshop allows the graphic designer to create much more complex files than ever. Banding can occur when multiple layers are used with different layer modes like “overlay” and “color dodge.” Photoshop now allows more rich textures than ever, but this can create unexpected results. For example, a layer of black on multiply on a layer of black, will produce a blacker black in the overlap area. This can’t be seen by they eye without using the proofing tools. Take a look at this example, a screenshot of photoshop. The black window has two different blacks in it, indicated by the red circles shown in the red and green eyedropper color palettes below it. The black looks solid, but may not print as a solid color.
Entry by: judy