The first patents describing conductive inks and their use for creating electrical interconnects were issued over 100 years ago. Additive processes comprising painting patterns of conductors and electroplating these to build up metals, or "print & plate" methods, originated around the same time as processes for etching away metals to create circuits. Alas etching based processes displaced mechanically connecting wires and became the entrenched method for patterning conductors on polymer based, non-ceramic substrates. These methods largely reined untouched for many decades and ironically the products are often called ‘printed wiring boards'.
The first revolution in additive manufacture of circuits occurred in the 1970's and 1980's with the commercialization of membrane touch switch technology 1. This is when printing Polymer Thick Film (PTF) silver conductive inks displaced etched copper processes to become the production method of choice for a number of everyday consumer electronics (calculators, keyboards, etc.). Today the question remains if some day the growing number of higher performance next generation conductive inks and additive production methods can all together displace the wasteful, environmentally unfriendly, and in many cases more expensive subtractive methods that have reigned over the last century.