Corner embroidery patterns specifically designed for the 45 degree angle. Many were originally for hankies but a corner is a corner…..and on this site it’s not called a border but then some designs aren’t well defined…….Good luck!
Both of these designs are from the 1800s. The braiding one works just as well with an outline stitch and the fleur corner is a redesign from the Ingalls catalog. Ingalls put out some beautiful patterns but a lot of them are incredibly busy with many kinds of flowers in one design.