We don't use Mylar for aligning the Printer to the PCB for printing paste because that is relatively easy to see if it is aligned, or else we use a pocket microscope; however, we use the Mylar for setting up the Glue portion of our printing process because the glue is being placed between the pads. Print gluing is faster than glue dispensing. Pocket microscopes can cost as little as $5.00 (very cheap), ours is about $50.
reply »