world-coordinate units for optimal performance, and so that no interpretation is needed for interpolation (stretching), deformation (shrinking), bitdepth translation, and color matching. When the cached graphic is to be displayed on multiple device types, multiple cached images are created to accommodate the different devices.
Cached graphics look almost exactly like their source MGraphic, but they may be gridded to integral device coordinates. When a cached graphic changes bitdepth, is rotated, transformed, translated, or scaled, the old cache is discarded and a new one is regenerated.