Continuous Ink Systems (CIS) are the revolutionary new ink systems, designed to make printing more efficient and effective. In contrast to conventional ink jet printer cartridges, CIS are a bulk feed solution, which means that you get more ink. Continuous Ink Systems were introduced in 1999, however have had a significant growth in the consumer market over the last few years. The problem associated with regular ink jet printer cartridges is the cost. The price of cartridges varies depending on the printer model and brand. However because cartridges contain very little ink - there is very little value.