“Here, a group of specialists with unique training, skills, and experience will, on request, design and develop a wide variety of heraldic devices for official agencies of the [US] Federal Government. Coats of arms, shoulder sleeve insignias, decorations for bravery, campaign medals, badges for skill and proficiency, and other identifying devices.”
An interesting short video from 1969 on The Institute of Heraldry (TIOH), based in Fort Belvoir, Virginia, United States.
56th Artillery insignia, 1969.
“The specifications are extremely precise. In the case of an embroidered shoulder sleeve insignia, the exact stitch count is described.”
The Institute website has a database of all US Army decorations, medals, and ribbons.