A protective cover which is generally in the form of a flexible bellows construction secured at each end by collars in order to define an interior space includes vent means. To evacuate air from the internal volume after the open top edge has been closed, the bag includes a one-way valve element attached to the first sidewall and communicating with the internal volume. The first output signal causes the wireless adapter to enter into an active audio channel mode. While moving the pattern original and the substrate, the entire die pattern is sequentially illuminated according to an exposure order, and the die pattern is demagnifyingly transferred to the substrate on which the images of the illuminated pattern portions are stitched together. The Presenter configures the first computer to select a region on its display for integration into the session.