There seems to be a new (or maybe old) fad around where people are using printers to make tattoos that they then apply to their skin. As someone who formerly worked in printing places and has witness some nasty reactions to inks, solvents, and the like, I’ll be the first one not to tell yo how to do a printer tattoo, and will say instead to please go do your homework before you decide to become an overnight tattoo artist.
Due to the wide variety of inks and dyes, there is no one simple answer as to the dangers of printer tattoos because the inks are comprised of a wide variety of substances which vary according to manufacturer and printer type. One way to find out what is in the ink or toner, and I do recommend you contact the manufacturer of your particular printer and ask them to send you their material safety data sheet on the particular ink it contains, or get this info from whoever refills your cartridges. MATERIAL SAFETY DATA SHEETS, study them, know them well, make them your friend.
Rule of thumb: if you can’t eat the ink, don’t put it on your skin. The skin does absorb what is put on it. If what is put on it can cause kidney or liver damage, or hives, or blisters, or any other number of ill-effects, one can take up a chair in the office of a professional tattoo artist or henna artist. As a professional, I would not ever use a printer tattoo, and hope nobody else tries it before thorough research. Here’s a couple of sites that offers some insight on printers that I think you will also find helpful:
P.S. Please also get henna from reputable sources which test the purity. Do not use black dyes for the same reasons as above. Henna as seen in pic should stain from red to brown, not a true black.