A "quilted" maple tree

The abnormal consistency of the wood results in an unusual pattern when the wood is cut tangentially - coveted by makers of guitars:

There was very little useful discussion at the Reddit source for the tree photo, or at the Wikipedia entry where I found the guitar photo (cropped for size).  There is some discussion at The Wood Database.  The process reminds me of tree burls, which are also prized by woodworkers.