Vallet used a disciplined burin technique to define volume and light. His portraits of figures like Jean Louis Guez and Miguel Molinos are notable for their restraint. He favoured the physical presence of his subjects through steady hatching and clean contours. This approach created a sense of permanence in his work. He avoided the visual clutter common in some Baroque prints. His work often features a balance between the subject and the surrounding space.

Modern collectors appreciate the stark clarity and historical detail found in Vallet's engravings. These prints offer a direct connection to the intellectual circles of the French Baroque era. The black-and-white compositions provide a sophisticated addition to a gallery wall. They bring a sense of history and technical skill to a modern living space. His religious scenes, such as the Adoration of the Kings, offer a different perspective on classical themes.