I horde it up and use it as a free weed block layer in the garden beds under the mulch.
All that dye may not be good for the plants. And, some if it may get sucked up into your tomatoes.
People with tattoos are just beginning to realize that the dye in their skin from their tattoos can/is having serious health effects.
Bad news for tattoos - Many tattoo inks contain dangerous heavy metals, phthalates and hydrocarbons