TMC Hallcrest manufactures a range of Thermochromic products using Leuco Dye technologies. These supplied in a variety of forms under their brand names Chromazone (reversible) and Kromagen (permanent).

We mix numerous Leuco Dyes with colour developers and a series of fatty acids, esters and alcohols that each have defined melt points to provide a range of materials that respond to different temperatures producing a variety of colours.

These products all change colour over a temperature range specific to their formulation providing a simple cost effective method of monitoring temperature.


  • Correct use or operation Indication
  • Safety warnings
  • Quality Control
  • Process Control
  • Interactive Packaging
  • Advertising messages


Temperature range

  • Chromazone -20 to 70°C with a large number of standard temperature available.
  • Kromagen 60 to 170°C with a number of standard temperature available

Colour Change

  • Chromazone Blue, Black, Red, Orange, Green and Magenta available as standard with many more produced on request. 
  • Kromagen Black, Blue and Magenta available as standard with more available on request 


  • Chromazone Aqueous Slurries, Powders, Inks, Plastic concentrates and Labels. 
  • Kromagen Aqueous Concentrates, Inks and Labels. 


  • Slurries, Concentrates, Powders and Inks are available in a variety of pack sizes from 1 to 200 kilo drums
  • Labels can be produced in a variety of Custom sizes, shapes and materials offering a bespoke solution designed to suite a wide range of applications