Q : One thing I did notice is that when using dry erase markers, there is a difference on the grey surface opposed to the white.

Either screen will fully erase even the residual markings as long as our specialized whiteboard eraser is used. Both versions of the whiteboard screen are surfaced in a scratch-resistant optical nanotech resin that enables them to perform their dual-role. This surface allows either screen to be matte enough for a projected image without hot-spotting, but smooth enough to erase pen strokes. Because of the unique texture in its design, a regular store-bought whiteboard eraser will work but it may not completely clear away the residual markings. However, the grey surface of the Starbright™ 4 material does made difference to readily identify any residual markings over the bright white surface of the “white” WhiteboardScreen™ Universal.