His style reflects the technical precision of the Düsseldorf School. He focused on clear draughtsmanship and a controlled use of colour. While many of his contemporaries pursued broad Romantic themes, Schwartze preferred the quiet dignity of individual subjects. This is evident in his 1844 Self-portrait, where he uses a neutral background to direct attention to the character of the sitter. This method creates a sense of presence without relying on theatrical lighting or busy compositions.

Modern collectors value his work for its directness and lack of sentimentality. These paintings provide a window into nineteenth-century Dutch life through a lens that feels remarkably modern. The balance of soft skin tones against dark clothing makes these prints suitable for contemporary interiors. His portraits offer a calm aesthetic that avoids the clutter of more decorative Victorian art.