Unable to calibrate using Firefox

[DavidGriffith]

I don't know if this problem lies with bitcoinpaperwallet or Firefox. I filed a bug report over at https://bugzilla.mozilla.org/show_bug.cgi?id=1178056 just in case. To restate the problem here, Firefox seems to thwart or ignore my attempts to change the zoom and/or horizontal scale parameters. If I print the calibration sheet with the "ignore scaling and shrink to fit page width" checkbox in the print dialog checked, I get an image that's somewhat in scale, but offset about 3 or 4mm too far left. If I uncheck that box, the best I can get is a ruler that's too big and the right side of the box is cut off. Monkeying with either parameter positive or negative only makes things worse.

Calibration does work perfectly with Chrome and parameters of zoom=5 horiz=5. I'm using Debian 8 with a Brother HL-5250DN monochrome laser printer.