Animal safe ink or dye

Question
Dear Expert,

My wife and I adopted the hamster from the grandchild of the late famous science fiction author Kurt Vonnegut. We have had her for about a year and a half and we love our Junebug Vonnegut-Von Glahn, but she  is showing serious signs of aging and we fear illness.  As a keepsake of our beloved first pet together, we thought it would be cute if we could get some animal safe ink or dye to get a paw print on a Vonnegut book before her end.  However, we obviously do not want to do anything that will jeopardize the health of our aging hamster.  Is there a particular product we can use for this that will be hamster safe?  I look forward to hearing your advice.

Thank you,
Nick and Sara

Answer
Hi Nick and Sara

I don't know of an animal-safe dye - I would think that a vegetable coloring would be safest, like beetroot or similar, but the only problem is that I don't know how long it will last on paper before it fades away. I definitely wouldn't use ink as your hamster will keep licking herself afterwards.

Sorry I can't be more help - hope you find a product that you can use.

Regards