What are cache files and does my printer or service bureau need them?
Cache images are created by Quark ALAP ImagePort when you first place a native Photoshop image. They contain a low-resolution preview for the layers and channels. The cache file is used when you place the same image twice into a QuarkXPress project. Your printer or service bureau does not need these files. At print time, Quark ALAP ImagePort or the Print-Only version of Quark ALAP ImagePort builds a full-resolution cache image using all of the settings applied through the Quark ALAP ImagePort palette.