HqnImpose2 page trimming and Trailer

This page applies to Harlequin v13.1r0 and later; both Harlequin Core and Harlequin MultiRIP.

By default, the last flat of every job is "trimmed" by setting negative margins if there is unused space. The left margin is always set. In GUI versions of the RIP, if Trim page has not been checked in the Page Setup dialog, the top and bottom margins are also set to negative values if there are no objects extending to the edge of the film. This behavior is controlled by a procedure called /Trailer. Alternative trimming mechanisms may be implemented by defining alternative procedures—the simplest is to disable any trimming by defining /Trailer as {}. Any margins from page setup are added to the values calculated by the Trailer procedure.

By default, blank flats within the job are suppressed. This is important to note when using (mainly one-up) impositions to add, for example, margins or scale to fit and so on, as it can be a surprise when blank pages from the job don’t appear on the output.

The solution is to use a null trailer procedure. For example, add the following to the imposition set-up dictionary if you want blank flats to be produced:

/Trailer {}

The reason the procset does this by default is because it was originally designed to save expensive film when making plates using film setters.