Does opening a ripped (Rampage) .PS file in Illustrator, and placing it into a layout (sized and positioned for a board size for a particular die cutter, but not messing with the dielines themselves, other than placing them in position in the Illustrator layout) have any effect at all on how the CAD system interprets the numbers? Does the thickness of the stroke in Illustrator cause the CAD system to offset the dieline (we've been using half-point strokes for dielines, but wonder if a quarter-point would be any different?)
The problem that we keep having is everything is "mathematically correct" (EXACTLY as Preps has imposed the layout), but sometimes the finished die will come back and be a couple of points off from one end of the die to the other. We specialize in paper swatchbooks, and the fit of the dies is critical (as there is little tolerance for ink to hang out over a score). We haven't been able to get to the bottom of this, although we've basically ruled out any problems on press.
Most of the time, these are straight horizontal or vertical lines. We don't always have time to wait for a press sheet before ordering the die (although that is our preferred method, of course, to send the sheet to the diemaker so they can confirm the fit of the die). We used to run a paper proof on our Epson 10000, and then a mylar proof of the dieline (although that is a whole new problem, because due to some change in the manufacture of the mylar, it always ends up coming out smaller than the paper proof). So now we've resorted to a paper-to-paper comparison, laid on a light table, to confirm that the die fits. In a perfect world, we could just go ahead and send the dieline to the diemaker without going through all of this (because we know everything is correct by the numbers), but our diecutting operator insists on viewing the dieline before we proceed with ordering the die.