Learn chain mail with Lauren Anderson, Part 4. Aspect Ratio: What is it and how do you calculate it? The ChainMaille Lady. Aspect ratio (AR), something that is critical to know when you're trying to adapt a pattern, either to make a new variation, or to work with the rings that you already have! Chainmaille. Chain mail. Bead&Button magazine. FacetJewelry.com. Facet Jewelry. BeadStyle. Jewelry making.