The "natural" color topsheet material we offer is essentially thin p-tex material abraded on one side for bonding.  The material is semi-transparent at first, but after the layup process and when the epoxy cures, the material becomes more clear.  For example, see the following photos below:

Just before going into the press: the topsheet covers the graphic layer.  The graphic shows through, but the topsheet is not 100% transparent, but more like "cloudy".

The result after pressing -- graphics show through nicely: