There are a number of companies that sell blank patches - Stadri Emblem is one I've purchased some from. If you want to make your own, the 'right' way to finish the edged is with a merrowing machine but they are not easy to find.
I've made a few for people but we sew them directly onto the garment as an applique using a satin stitch on the edges.
I've made a few for people but we sew them directly onto the garment as an applique using a satin stitch on the edges.