The Paris Salon frequently rejected Rousseau's work, the official art exhibition of the Académie des Beaux-Arts in Paris. This was mainly due to his insistence on depicting nature in a more raw and unidealized form, which challenged the academic norms of that time. "The Forest of Fontainebleau" by Théodore Rousseau is an example of such painting, a richly detailed landscape painting that captures the untamed beauty of the French forest at Fontainebleau. Strong, knotted trunks of old oak trees powerfully rise from the forest ground and take up most of the space in the piece. Very small, fine lines are used to draw the underbrush, creating multiple levels of surfaces. Light plays a crucial role in this composition, as the sun flows through the canopy, making patterns of light and shadow that give the scene a dynamic quality. The leaves move in a spectrum of greens, yellows, and browns, demonstrating Rousseau's use of color. A peaceful stillness and calmness infuse the scene, inviting the viewer into a contemplative space deep within the landscape.

Rousseau's painting is a careful study of the forest's natural qualities. It focuses on direct interactions with nature instead of previous artistic traditions such as dramatic, human-centered storytelling. His work represents the Barbizon School's reaction against Romanticism's theatricality and Neoclassicism's exact precision. Instead, it embodies a deep respect and fascination for the natural environment, focusing on a local forest's sublime beauty rather than exotic or imagined scenes. He depicts the forest with a sense of authenticity, reflecting the Barbizon School's practice of painting en "plein air" directly from life. Therefore, the forest is not a setting for another subject; it is the main character itself. "The Forest of Fontainebleau" thus portrays nature as a living, breathing entity, which influenced the course of art history by breaking from convention and laying the groundwork for the Impressionists who sought to capture the transient moments of natural light and atmosphere.