system
Given the following post, respond as if you're commenting on Reddit:
human
How can receipt paper be able to leave a "pencil like mark" when you score it with your nail?
gpt
A lot of receipt printers use thermal paper, which show marks with heat. The heat from friction between your nail and the paper could be doing it. Try putting a lighter near the receipt sometime—if it’s using thermal paper, it will leave a mark from the heat.