Printing, Screening, and Sharpening

The very process of printing an image tends to soften it. So when applying sharpening to a print-bound image, you will want to compensate for the softening to come. Printing involves the use of a halftone pattern, which can exacerbate any additional patterns that exist in your image. So on the one hand, printing can soften high-contrast edges, and on the other, it can make unwanted patterns worse. The takehome message is to remove any patterns or artifacts that you do not want, and then sharpen a bit more than you would for simple onscreen display.