Do you really need an entire grid? If you can live with etching one at a time, I would print the design on a regular piece of paper and then cut out the toner transfer (inkjet) paper just slightly larger than the design and tape it over the printed area on the plain paper. Feed it back through the printer, and viola! as they say.
You could possibly get around the security by printing to (yet another) PDF and then manipulating that with Gimp, Preview, or some other image editing program. Just seems like you could run the risk of getting the scaling and resolution out of whack…