Much like leather, horn buttons are a byproduct of the meat industry. The buttons come from from keratin, the incredibly strong structural protein that makes up everything from hooves to feathers to tortoise shells. They are usually made from ox or buffalo horns, and the buttons are cut out of the upper hollow part of the horn while the toggles—like you’d see on a duffle coat—are made from the solid tip. Using high pressure and heat, the horns are flattened so that buttons can be punched out of the horn.
Horn buttons—like many other natural products—are known for their rich, deep, color. They have a beauty that is difficult to capture in an imitation. The finish can be anywhere from a rough, weathered look to a highly polished shine, but any good horn button will have a radiance that no plastic copy can reproduce. If you hold a horn button up to the light, you should be able to see some amount of translucence as well as variations and imperfections that are the hallmark of a natural product.
Horn buttons can come in a wide array of shapes and sizes, but because they can be made much larger than mother-of-pearl buttons they are most commonly used for tailored clothing, outerwear, and pants. They can easily cost 100 times as much as a similar plastic button, but there’s no substitute for the real thing.