Drying can be accelerated by placing the finished prints in a 25°C to 30°C environment with continual air movement. Depending on the inks and paper combination, drying time may be more than 24 hours.
They are very resoluble and are often favored in graphic printing on paper or board. Solvents in printing inks evaporate as the inks dry, releasing Volatile Organic Compounds (VOC’s) into the atmosphere.
Water-Based Inks
These inks are based on a combination of acidic resin held in solution by amine and water-borne resin dispersions known as emulsions. Solution resins aid print quality, and the emulsion is used to provide resistance properties in the dried ink. During drying, on absorbent surfaces such as paper and board, the ink components will start to penetrate into the substrate. Evaporation of water and amine takes place at the same time, often aided by dryers on the press.
The liquids (water, oil & solvent) act as a carrier of a dye or pigment onto a given substrate. The jetting system in the printing mechanism defines the types of inks that can be used, e.g. Thermal Ink Jet-> water-based only, Piezo Ink Jet-> water, oil, solvent, etc.. and in turn, decides the specific substrates that are required for the inks.
Dye-based inks are not generally waterproof and can fade quickly in direct sunlight, hence normally recommend to be used for indoor graphic only.
Pigment-based inks use insoluble colourants which are highly water and fade resistant. They are used for outdoor as well as indoor graphics. They may however offer slightly muted colours.
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