Stress-meter ink

Silk Screen Holland is continuously on the look-out for novel and exciting applications for ink. One example is temperature-sensitive stress-meter ink. Perhaps you are familiar with the 'How in love are you?' greeting cards. In its cold form, this ink is transparent and appears dark grey on its black background. Depending on (body) temperature, the printing changes colour:
 

• from 20 degrees Celsius to 24.5 degrees Celsius the ink turns red
• from 24.5 degrees Celsius to 25 degrees Celsius the ink appears green
• above 30.34 degrees Celsius the ink appears blue

Take note: this ink requires a background of completely dry offset ink that is 100% matt black. The effect and longevity of the ink reduces considerably when it is exposed to temperatures above 80 degrees Celsius for longer than a minute. When the ink is compressed by, for example, a cutting block, die-cut rubber, or steel band, it loses its temperature sensitivity entirely.

Customised temperature range possible with larger print runs:
 

• The range preferred for green is the deciding factor (20-25, 25-30 or 30-35 degrees Celsius)
• At a few degrees cooler, red is the first colour to appear
• Blue follows after green