Bulk mail is often produced using a letterpress-style machine. Personalized mail, on the other hand, is usually "handwritten" using a pen plotter (e.g., AxiDraw

Bulk mail is often produced using a letterpress-style machine. Personalized mail, on the other hand, is usually "handwritten" using a pen plotter (e.g., AxiDraw). https://axidraw.com/ https://axidraw.com/