Dye interacts with the wood, yielding a multilayered look.
Sugar maple is one of my favorites because the curl is amazing, but the medullary flecks don’t accept dye as readily, so they seem to float over the curl.
Here’s a closeup–the medullary flecks are visible in the top right corner of the image.
This is the sugar maple back showing the whole color range.
Here’s another photo of the back, toward the upper bout.
