[MAC] DPL unresponsive while preparing for print

DPL 4 (on Mac) gets unresponsive while a (series of) print(s) is prepared for output. When a series of prints is prepared, all images are prepared first, before the first image will be printed. Both of these properties feel old fashioned.


  1. Change resource allocation so that DPL can be used while prints are prepared
  2. Prepare and print in parallel or make it user selectable: batch or parallel processing.