The most important part of the inkjet printer is the ink that is used in the cartridge. The quality of printing is directly affected by the quality, type and amount of ink in the cartridge. Inkjet inks are designed for use in specific printers or print heads.
Inkjet inks can be classified into the following categories: water based, solvent-based, oil-based, UV-curing and hybrid ink. Water based inkjet inks have no volatile organic compounds and have low toxicity. This slows down the drying rate in non-absorbent surfaces. They are not suitable for high resolution printing as they tend to feather or bleed. These inks are generally used on paper, while solvent-based inks are typically used for commercial printing like coding and marking on cans and bottles. They dry faster but emit volatile organic compounds. Oil based inks are used for card printing, packaging, labels and boxes where ink is fully absorbed. As the droplets can be formed with very small quantities, they can be used for high-resolution printing. Oil based inks tend to clog if left unused for long period of time but need a special medium to ensure proper drying. UV curing inks are used in high quality printing. These inks do not emit volatile organic compounds, and are so environment friendly. These are used in applications that require excellent durability such as card printing and billboards. They cure only when exposed to UV light. The cost of UV curing ink is higher than any other ink but requires low print head maintenance. Hybrid inks are a combination of two or more of the above mentioned varieties. Although they are high in cost, they ensure better control of resolution.
Every new development in printing has brought in a suitable modification in the ink used.
Different types of inks are used for different applications depending on various factors like cost, quality and durability.