Summary form only given. Plastic thin film transistors (TFT) offer the potential to be fabricated using low cost manufacturing techniques, e.g. lamination, printing, and reel-to-reel processing. Possible applications include displays, large area electronics, radio-frequency identification tags, sensors, and toys. This paper discusses the materials chemistry, device design, and processing issues involved in making arrays of plastic TFTs. In particular, the paper reviews the status of TFTs on flexible substrates in display applications.