Tattly temporary tattoos can be used on your skin or on your S'well bottle. They last at least 2-3 days. S'well set includes 8 Custom Tattly tattoos, designed in the fun and fashionable S'well spirit. To apply, remove the plastic from the front and place it facedown on your skin or bottle. Wet your sponge and press it onto the back of the tattoo, holding it in place for 15 to 30 seconds. Slowly peel off the paper to reveal your new (temporary) ink!