Oil Painting Grounds: Danish Golden Age Preparation Layers

Understanding oil painting grounds is essential for controlling adhesion, absorbency, flexibility, and long-term stability in painting. The preparation of a canvas determines adhesion, absorbency, flexibility, and long-term stability. Much of what is commonly taught about historical grounds derives from manuals. However, manuals often describe idealized practices rather than what artists or suppliers actually did. This study analyzes nine Danish Golden Age paintings to determine the real materials and structures used in their preparation layers (Andersen et al., 2017, pp. 2–3).

The authors used SEM–EDX for elemental analysis, FTIR for molecular identification, and GC–MS for organic binders. Samples were taken from tacking edges, ensuring that all preparation layers—from canvas upward—were included (Andersen et al., 2017, p. 3).

Historical Context: Grounds and Sizing

Traditional preparation often involved a glue size applied to raw canvas, followed by one or more ground layers. These grounds could include pigments, fillers, and binders such as oil, glue, or emulsions (Andersen et al., 2017, p. 2).

However, nineteenth-century practice was changing. Commercially prepared canvases became more common, and materials were adapted for storage, transport, and flexibility. These practical concerns likely influenced the formulation of the ground (Andersen et al., 2017, pp. 2–3).

General Composition of Oil Painting Grounds

Across all nine paintings, the grounds show a striking consistency:

• Pigment: lead carbonate (lead white)
• Fillers: calcium carbonate, often calcium sulfate; occasionally silicates or barium sulfate
• Binder: drying oil combined with egg

Most importantly, no collagen-based glue sizing was detected. This conclusion is based on the absence of hydroxyproline in amino acid analysis (Andersen et al., 2017, p. 10).