The inkjet printer uses the principle of a set of tiny jets used to squirt a fastdrying ink at the paper. The two main systems currently are the bubblejet™ and the piezoelectric jet. The bubblejet system, devised by Canon, uses a tiny heating element in each jet tube, and an electric current through this element will momentarily vaporize the ink, creating a bubble that expels a drop of ink through the jet. The piezoelectric system, devised by Epson for its Stylus™ models, uses for part of the tube a piezoelectric crystal material which contracts when an electrical voltage is applied, so expelling a drop of ink from the jet. Both methods can provide high resolution and are adaptable to colour printing.