As i want my print back to be a gift something that is a surprise or a secret i felt i was more than appropriate to have a research into some interesting ink processes that would benefit my design...
THERMOCHROMIC INK
Thermochromism is the property of substances to change color due to a change in temperature. A mood ring is an excellent example of this phenomenon, but thermochromism also has more practical uses, e.g. in baby bottles (changes to a different color when cool enough to drink) or kettles (changes when water is at or near boiling point). Thermochromism is one of several types of chromism.
The two common approaches are based on liquid crystals and leuco dyes. Liquid crystals are used in precision applications, as their responses can be engineered to accurate temperatures, but their color range is limited by their principle of operation. Leuco dyes allow wider range of colors to be used, but their response temperatures are more difficult to set with accuracy.
Some liquid crystals are capable of displaying different colors at different temperatures. This change is dependent on selective reflection of certain wavelengths by the crystallic structure of the material, as it changes between the low-temperature crystallic phase, through anisotropic chiral or twisted nematic phase, to the high-temperature isotropic liquid phase. Only the nematic mesophase has thermochromic properties; this restricts the effective temperature range of the material.
Activation temperature points range from low refrigeration type temperatures through normal body temperatures to high temperatures that exceed the pain threshold.
PHOTOCHROMIC
Photochromics change from clear when indoors to color when outdoors. Specifically, PC’s change color in response to ultraviolet light, usually from the sun or a black light.
Photochromic behavior can be either Reversible or Irreversible. (Technically, all photochromism is defined as reversible but for simplicity we will use the term irreversible photochromic to describe irreversible photochemical reaction that yields a visible color change.)
Reversible Photochromics transform from clear to color by changing their chemical structure after absorbing UV light, usually from the sun or a UV light. The UV light causes the PC’s to absorb color (like a dye), and then change back to clear when the UV source is removed. They can cycle thousands of times depending upon the application. They can also change from one color to a different color by combination with a permanent pigment. Standard LCR Hallcrest photochromic ink will change from clear to color when activated by UV light.
The most famous reversible photochromic application is color changing lenses for glasses, as found in Transitions® eye-glasses. Reversible PC's are also found in novelty applications such as Tee Shirts, toys, cosmetics, and industrial applications.
Inks change color when exposed to ultraviolet light usually from the sun or a black light. The inks are effectively colorless indoors and turn into vibrant colors outdoors. When brought back inside, the inks become clear again. The inks become intensely colored after only 15 seconds in direct sunshine and return to clear after about 5 minutes indoors. Perfect for textiles and other applications where there is a period of exposure followed by non-exposure to UV light.
HYDROCHROMIC
It is a special white ink, which changes repeatedly from white to transparent when wetted with water and changes back to the original white when dried, for screen printing onto Paper ,Umbrella cloth,Plastic printing design etc.The vivid color design is concealed with white in dried condition and appears when the ink becomes transparent with water.
I think that Thermochromic ink and Photochromic would be the most appropriate as i wouldn't use hydrocrhomic ink for print book as there would be no need for it to get wet.
- Cold Activated Thermochromic Ink is used on labels and packaging to create a color change when cooled. (Clear to Color at 15ºC / 59ºF)
- Touch Activated Thermochromic Ink will vanish when rubbed or touched to reveal an image or another color printed beneath. (Color to Clear at 31ºC / 88ºF)
- Touch Activated Liquid Crystal Ink will change color within the visible spectrum when rubbed or touched. Color Sequence: Black » Red » Green » Blue (25-30ºC / 77-86ºF)
- High Temperature Thermochromic Ink is designed to change color just below the pain threshold alerting consumers and users to a safety hazard - Too Hot! (Color to Clear at 47ºC / 117ºF)
PHOTOCHROMIC
Photochromics change from clear when indoors to color when outdoors. Specifically, PC’s change color in response to ultraviolet light, usually from the sun or a black light.
Photochromic behavior can be either Reversible or Irreversible. (Technically, all photochromism is defined as reversible but for simplicity we will use the term irreversible photochromic to describe irreversible photochemical reaction that yields a visible color change.)
Reversible Photochromics transform from clear to color by changing their chemical structure after absorbing UV light, usually from the sun or a UV light. The UV light causes the PC’s to absorb color (like a dye), and then change back to clear when the UV source is removed. They can cycle thousands of times depending upon the application. They can also change from one color to a different color by combination with a permanent pigment. Standard LCR Hallcrest photochromic ink will change from clear to color when activated by UV light.
The most famous reversible photochromic application is color changing lenses for glasses, as found in Transitions® eye-glasses. Reversible PC's are also found in novelty applications such as Tee Shirts, toys, cosmetics, and industrial applications.
Inks change color when exposed to ultraviolet light usually from the sun or a black light. The inks are effectively colorless indoors and turn into vibrant colors outdoors. When brought back inside, the inks become clear again. The inks become intensely colored after only 15 seconds in direct sunshine and return to clear after about 5 minutes indoors. Perfect for textiles and other applications where there is a period of exposure followed by non-exposure to UV light.
HYDROCHROMIC
It is a special white ink, which changes repeatedly from white to transparent when wetted with water and changes back to the original white when dried, for screen printing onto Paper ,Umbrella cloth,Plastic printing design etc.The vivid color design is concealed with white in dried condition and appears when the ink becomes transparent with water.
No comments:
Post a Comment