Abstract: The present invention relates to an interactive touch system on a transparent medium and more particularly, the present invention relates to a method and system for improving the contrast of writing on an interactive touch system on a transparent medium. The interactive device has an interactive surface having an interior side and an exterior side. The interior side is observed by at least one emitter and at least one detector. The interactive surface has a privacy layer; the privacy layer transforming between a transparent and a non-transparent state. A processing structure executing instructions detects a pointer contacting the interior side of the interactive surface; and applies a signal to the privacy layer to transform the privacy layer into the non-transparent state.