Wood prints are a rather new and less known medium.  The image is printed on a 1/2 inch piece of maple wood that is first painted over with a layer of white paint to let the image pop more.  You can see traces of the wood grain still in the image but with the layer of white before printing the wood tones become more muted.  For images with sky this kind of print can be very unique.  There is a wood hanger on the back for hanging without the need for a frame.