I bought a piece of sweet gum slab sand had it surfaced. The picture of it freshly cut showed a heart wood stripe about the color of walnut with a wide white/blond sap stripe on both sides. To be honest, when I picked it up the stripe was not very prominent. Had it flattened and thinned a bit on a CNC yesterday. Went to pick it up this morning and the guy who ran the machine was bragging about the beautiful stripe. By the time I got there the stripe had faded to to tan.
What can I do to keep the stripe prominently visible?