Since the image quality in the PDF instructions didn't come out absolutely wonderfully, I'm making available to JaS two files in Hewlett-Packard PCL-3 format. (lpstrob.prn and lpsmirr.prn = same copper artwork but a mirror image, for those who want to use Press-'n'-Peel)
They work with any HP or other-brand PCL printer from the Laserjet-3 on (maybe earlier ones too, and I think the Deskjets understand PCL as well), and will give the best possible printout quality.
Most importantly, they will print out at exactly the right scale - which is important when trying to get the components to fit into the holes in your finished board.
Once you have the file in Windows, open a DOS window, and use a binary copy command to get it to the printer:
eg (if your printer is on parallel port 1):
c:\> copy /b c:\downloads\lpstrob.prn lpt1:
Sorry - I cannot speak macOs, so you'll have to read the book!
For those with USB printers, here's info on how to copy binary files to them:http://www.decompile.com/dataflex/tips/usb_printer.htm