I shuddered when reviewing this ink marker exercise. Ink doesn't erase and tends to spread a bit. The pens have large and small tips, and even the small tips seem likely to bump into neighboring detail.
Well, after all that hand wringing, I'm rather thrilled with the results. My small set of markers doesn't include any whites so I went with Bombay white india ink and a brush for the pine sap. The markers do allow for blending and I was able to pull the black with umber to create some transitioning. Also slipped in a bit of orange for highlights.