I worded it a bit ambiguously before — I’ve corrected it since. I wasn’t referring to printing the private key (that should of course never be entered into any device other than a hardware wallet), but to the punching guide. When using TitanDot, you punch the binary index of the seed words into the plate. For this, there’s a punching reference sheet. My advice is to print that guide (and verify on Github) and perform the punching in a place where you’re not surrounded by network-connected devices or cameras.