Model-based halftoning techniques exploit the properties of the display device and the human visual system to maximize the quality of the displayed images. They rely on accurate models of the display device and human perception. The focus of the tutorial is on printers but similar techniques can be applied to other display devices. We will first review traditional halftoning techniques. Then we will consider various model-based techniques, including error diffusion with a printer model and least-squares model-based halftoning. Both algorithms produce images with high spatial resolution and visually pleasant textures. We will also consider the use of printer and eye models in blue-noise screening techniques, which attempt to approximate the performance of error diffusion with minimal computation. We will examine the performance of these halftoning techniques using both model-based quality metrics and subjective evaluations. We will consider both black&white and color halftoning.