"Black-strakes, a range of planks immediately above the wales in a ship's side; they are always covered with a mixture of tar and lampblack, which preserves the plank itself, and forms an agreeable variety with the white bottom beneath, and the scraped planks of the side, covered with melted turpentine, or varnish of pine, above. All the yards are likewise daubed with this mixture, which not only preserves them from the heat of the sun and the weather, but gives them a fine gloss, which makes a good appearance, contrasted with the white varnish on the masts."
—Falconer's New Universal Dictionary of the Marine (1816), 41
"...most exceptionally it took place on a Sunday when church was rigged, and even more exceptionally it took place in a newly-painted ship, with all hands acutely aware of their best clothes on the one hand and of the wet paint, the freshly laid-on pitch tar, and the still-moist blackstrake just above the wales on the other."
—Patrick O'Brian, The Far Side of the World, 163–164