Free Form Projection Display is a novel display technology to superimpose a virtual object onto real object by image projection. The method is based on the distortion cancellation algorithm to project an image onto curved screen without distortion. The virtual object is represented as if it is located inside the screen. This system allows the user to handle the screen object directly, and gives the user a feel of motion parallax. This system gives the user the ease of perception of positional relationship between the surface of screen and the internal virtual object. For this novel interaction system, it is important that the user can see clearly not only images on the screen but also shape and curve of the screen itself. In this paper, we focused the effect that the texture of screen surface gives the depth cue. Visibility of screen surface was discussed and evaluated through experiments. ©2008 IEEE.