To Measure Post Caps: Take the widest diameter across the top of your deck post. Cap styles are made in 1/4" increments. It is up to you if you want them to drop over the posts or simply chisel some material away for a snugger fit. Notes: All copper is provided in the natural state and will develop a beautiful patina over time. Copper does go through a darkening and uneven color stage in the process. Minor mars, imperfections, and/or color variations are characteristics of copper and virtually disappear as copper ages and develops its' patina. Due to the custom nature of these products, we are NOT responsible for improper measurements provided to us.