alt Hacker NewsDepending on the make and model, send a reverse feed code and then overwrite with block characters. You will know that something bad happened, but you won't know what.
Depending on the make and model, send a reverse feed code and then overwrite with block characters. You will know that something bad happened, but you won't know what.
That makes it inconvenient to read, not impossible. E.g. use transmitted instead of reflected light (shine a bright light behind the paper) to see how much ink is in each place.