Ritter specialised in portraiture and miniatures, often working with chalk and watercolour. His style avoids the stiff formality of earlier Baroque traditions. Instead, he adopted the clarity of the Neoclassical movement. In Portret van een man, mogelijk een zelfportret, he uses precise lines and subtle shading to define character. His compositions, such as Portrait of a Woman in an Oval Frame, often use simple backgrounds to keep the focus on the sitter.

Modern collectors value Ritter for his technical honesty and the domestic scale of his works. His drawings, including Mannelijk naakt, zittend op een blok, demonstrate a rigorous study of the human form. These works offer a sense of historical continuity without the overbearing weight of large-scale oil paintings. The neutral tones and balanced proportions provide a quiet aesthetic that works well in modern spaces.