As the most common writing material in our daily life, paper is an important carrier of traditional painting, and it also has a more comfortable physical touch than electronic screens. In this study, we designed a shadow-art device for human computer interaction called MagicPAPER, which is based on physical touch detection, gesture recognition, and reality projection. MagicPAPER consists of a pen, kraft paper, and several detection devices, such as AirBar, Kinect, LeapMotion, and WebCam. To make our MagicPAPER more interesting, we developed more than a dozen applications that allow users to experience and explore creative interactions on a desktop with a pen and a piece of paper. Results of our user study showed that MagicPAPER has received positive feedback from many different types of users, particularly children.