An interview with expert calligrapher Bernard Maisner, who does the usual wedding invitations, window signs, but has also had cameos in major films:

I did writing on-camera for a documentary film about the Oswald/Kennedy assassination by famed German filmmaker Willi Huismann. I had to write like Lee Harvey Oswald live on camera. Writing samples of Oswald were provided to me from the U.S. National Archive and Records Administration. I studied the writing, analyzed and made U&LC alphabet charts from Oswald’s writing, traced and memorized every letter, as well as his combinations of letters, and studied other characteristics of his writing so that I could write the way Oswald did—immediately and without thinking.