<p>Thermostar Hydrochromic Ink is available as Irreversible or Reversible. There are two types of Irreversible Hydrochromic ink; the first changes from a colour to white when exposed to water and remains so when dry again. The second dissolves and washes off the surface revealing a message below. The Reversible Ink is white in appearance but becomes translucent when exposed to water and then reverts back to a white state when dry.</p><p>These Inks can be featured in a variety of applications revealing that a product has been exposed to water, including high end promotional items, game cards, labels and packaging..</p>