Flexo

Flexo, short for flexography, is a form of relief printing that uses flexible plates made of rubber or photopolymer. It is the most common method for producing packaging and labels, but also used for newspapers, carpet backing, and other materials. The process prints with fast-drying inks on a variety of substrates including plastic, film, foil, paper, and metal.

The press uses a plate cylinder bearing the raised image, an anilox roller that meters a precise amount of ink, a doctor blade to control excess ink, and an impression cylinder to transfer the image to the web. The ink is applied to the plate, transferred to the substrate in contact with the impression cylinder, and then dried or cured, often with UV light. Modern flexographic presses use digital or laser-imaged photopolymer plates and may have multiple color units enabling CMYK plus spot colors in a single pass.

Inks used include water-based, solvent-based, and UV-curable varieties, selected based on substrate and end-use. Anilox roller technology and anilox cell geometry determine ink volume and print solidity.

Advantages include high-speed production, compatibility with a wide range of substrates, and cost-effective large-run printing. It is particularly well-suited for packaging, labels, tapes, and flexible materials. Limitations include relatively lower native resolution compared to offset and gravure, dot gain, and the need for careful ink and plate management, especially with solvent inks and environmental concerns.

Ongoing developments focus on improved plate durability, higher screen counts for finer detail, digital plate imaging, and more sustainable inks.