We are blessed (?) in our part of the Northwest with endless varieties of fungus. This lichen is only one of hundreds of types, and what textures each has!
I actually took this one new for the assignemt instead of digging into my files! In the basket aisle of Michael's in Issaquah. I had to (ah-hem) rearrange their display a little.
I had to go to my Hungary files because of this example. The old buildings are completely reflected in a large window of a more modern train station. You can see the window seam, and the little white squares are the window joints, but the entire picture is a reflection. Lucky for me it was a blue-sky day.