Print Power magazine is a European initiative dedicated to strengthening the position of print media in a multimedia world. It features some of the latest and best innovative uses of print in and around Europe, from real-life uses to thought leader debates and brand marketing techniques.

The Autumn 2013 (issue 06) edition focuses on how specialist inks and finishes can turn reading into a more exciting sensory experience. The cover of this issue uses Thermochromic ink to add an engaging element of interactivity to the magazine, with the area above the cover star’s head revealing a hidden message when heated or rubbed using a hand.

The Thermochromic ink was applied by Celloglas at their Reading factory using a screen process, as well as a spot UV around the hidden message to look like light rays emitting from the light-bulb.

What are Thermochromic Inks?

Thermochromic inks are water based (applied to media via screen print machines) and are primarily used to hide printed messages, however they can also be used as an anti photocopying device to increase security of documents. When rubbed the Thermochromic ink changes to a semi- transparent grey/white state, allowing the message underneath to be read.

What colours can the ink be?

Black is the only colour that will mask other colours. (Different colours are available but they will only mask very light tints of the same colour).

What is the optimum temperature for reaction?

Thermochromic inks can be manufactured to react at different temperature ranges – though they are most commonly set to react at temperatures close to normal human body temperature. (This allows for the underlying message to be revealed through the warmth of a hand)

‘Chill and Reveal’ inks are also available – these inks appear slightly translucent at room temperature, with a hint of the chosen colour, but change colour when chilled in a refrigerator. (Colours available: Black, Blue, Orange, Pink, Red + Green).