Finished Albright knot

Pass the tag end of the backing the opposite way through the loop as the standing end and work the coils of backing as close to the end of the loop as possible. Now pull both ends of the backing gently to tighten all the coils evenly. As they get tighter you can pull harder, and finally you can pull them so tight that the backing eats its way into the coating of the fly line, as it's seen here.
Be careful not to pull any coils out over the loop end. The two tags should wind up blocking the outmost coils. Trim the tag end, and you have a strong backing to fly line connection.