PostScript: How to Set Precision Bitmap Alignment



If I create a rectangle in MacDraw and print two copies to a LaserWriter, one
may measure 150mm x 200mm, and the other 151mm x 201mm. There is a variation
in both dimensions. Sometimes, however, they may match perfectly. I am using
the LaserWriter in a four-layer printing process and find this inconsistency
very annoying.

Because the variation is in both dimensions and the age of the LaserWriter is
relatively new, I believe the paper weight (which is within specification), the
paper finish, and the age of the LaserWriter are unlikely to be possible causes
of the problem. Can you help?

The size variance described is a result of PostScript interpretation of the
bitmapped image. This results from attempts to change a 72-dpi image into a
300-dpi image. This is not an exact ratio. There may be as much as a
4-percent variance in PostScript's interpretation. PostScript's attempts at
correction may vary slightly during each pass.

To compensate for this difference, choose Page Setup from the File menu. On
the right side of the Page Setup dialog box, there is an Options button. Click
this button, and an additional dialog box appears. The fourth checkbox is
labeled Precision Bitmap Alignment (4-percent reduction). Be sure this
checkbox is marked. Using this option increases the printing time. However,
the printouts will be consistent during each pass.


Published Date: Feb 18, 2012