[krunck]

Be careful where you print these. Most full-featured printer/copier/scanner devices found in office environments can store print job data on the HD where service technicians can access it.

[lozf]

There's always paper-age[0] for those who want to add symmetric encryption (via age) to their qr-encoded secrets! ;)

[0]: https://github.com/matiaskorhonen/paper-age

Edit: I now see it was already mentioned.

[yencabulator]

For extra fun, the printer is likely either on the network or has bluetooth. Age-old poorly written embedded computer with network services written in C is the industry standard. It's totally plausible to break in and steal previously-printed data.

[techwolf12]

I'll use my own printer, and after it dies on me, I will give it the Office Space treatment ;)