Are all bitmap graphics files of a high enough resolution?
The resolution of bitmap images generally needs to be between 1.5 X to 2.5 X the halftone line screen. So if we are sending an advert to a magazine which prints color pages using a 150LPI halftone screen, then our bitmap images will ideally be 300dpi (using Photoshop settings), at the intended printing size. If we are are scanning an image to be used for a 200LPI high quality brochure, then we may want specify a dpi of 500dpi. However, please see our designer’s resolution guide for more details about dots, pixels and line screens. • Understanding trapping. Discuss with the printer as to who is responsible for trapping settings. Although both Quark and InDesign have their own inbuilt trapping systems, many printers have high end systems that they prefer to use. If you have used any unusual trap settings, it may be best to discuss these with the printer. • Preflighting & flightchecking software. There are several tools that will check your DTP files and tell you about potential printing
