Import into Corel Draw and use raster not vector, to burn away the kapton film. For a 35W or 45W epilog, 30% speed and 100% power at 600 dpi made for a nice clean edge. Be sure to gently rub the stencil with water and a paper towel to get rid of the burnt kapton.

I usually use the Dimension layer info to make a jig for silkscreening by cutting out the PCB outline in a 0.062'' (1/16th) clear acrylic sheet.

Here is a LFCSP 16 (4mm on each side) cut out of 2 mil kapton as above.