Ulmer used technical precision with the burin. His approach focused on clear lines. He used balanced compositions. In engravings like Saint Cecilia Playing the Harp and the Madonna of the Green Cushion, he achieved smooth tonal gradients. He avoided heavy cross-hatching. This gave his engravings a quality that mimicked the texture of oil paintings. His Madonna della Seggiola demonstrates his ability to map complex circular forms onto a flat copperplate.

Collectors appreciate the crispness of these engravings. These engravings suit modern interiors. They offer a formal aesthetic in a black and white format. His portraits, such as Sir Sheffield or Beccadelli, provide a sense of classical order. The engravings are documents of nineteenth-century taste. They allow for the display of traditional religious subjects with a clean, graphic finish.