Printer ink doesn't contain animal products.
Here is an article about the chemistry inkjet cartridge ink:
Ink chemistry . Inkjet cartridge ink can contain eosin (a synthetic red dye):
Eosin Y - Wikipedia , triphenylmethane (a synthetic blue dye):
Triphenylmethane - Wikipedia , inorganic pigments, and carbon black (made from petroleum):
Carbon black - Wikipedia .
Could you please post a link to the article which claims that printer ink isn't vegan? They need to be notified about their misinformation.