Conductive ink is an ink that results in a printed object that conducts electricity. Transforming liquid ink to solid printing may involve drying, curing or melting processes.

These inks can be classified as high-solids fired systems or thick film polymer systems, which allow circuits to be drawn or printed on a variety of substrate materials (Substrate (Electronics)), such as polyester for paper. These types of inks generally contain conductive materials, such as powdered or flaked silver and carbon-like materials, although polymeric conduction is also known.

Conductive inks can be a more economical way to lay down modern conductive traces, when compared to traditional industrial standards, such as etching copper (copper plated substrates), to form the same conductive traces on relevant supports, as printing is a purely additive process that produces little or no waste stream, which then has to be recovered or treated.

Silver inks have multiple current uses, including printing RFID tags, such as those used on modern transportation tickets, they can be used to improvise or repair circuits on printed circuit boards. Computer keyboards contain membranes with printed circuits that detect when a key is pressed. Anti-frost windshields, which consist of resist strokes applied to the glass, are also printed. Many new cars have conductive traces printed on a rear window, which act as a radio antenna.

Printed paper and plastic sheets have problematic characteristics, mainly high strength and lack of rigidity. The resistances are too high for most circuit board jobs, and the non-rigid nature of the materials allows undesirable forces to be exerted on component connections, causing reliability problems. Therefore, such materials are only used in a limited range of applications, usually where flexibility is important and no part is mounted on the blade.