Before the widespread adoption of modern acrylic gesso, artists prepared their painting surfaces using a laborious, multi-step process that primarily involved glue sizing followed by a slow-drying, lead-based oil-based primer. This method created a suitable ground for oil paints but required significant time and effort.
Traditional Surface Preparation Methods
Historically, creating a proper painting surface was a time-consuming craft. Artists needed to ensure their canvases or panels were adequately sealed and primed to accept oil paints, which could otherwise degrade the support over time. This preparatory work was crucial for the longevity and quality of the artwork.
The Two-Step Priming Process
The traditional approach to preparing a painting ground for oil paints involved two distinct applications, separated by a substantial waiting period:
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1. Glue Sizing:
- Application: On the first day, artists would apply a layer of glue sizing to their raw canvas or wooden panel. Historically, this often involved animal glues, such as rabbit skin glue.
- Purpose: The primary role of glue sizing was to seal the porous surface of the support. This created a barrier, preventing the oils from the subsequent primer and paint layers from directly absorbing into or rotting the canvas fibers. It also helped to stiffen the fabric and reduce its absorbency.
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2. Oil-Based Primer:
- Application: The day after the glue sizing was applied, a slow-drying, lead-based oil-based primer was spread over the sized surface. This primer, often white, provided a smooth, non-absorbent, and opaque base for the artwork.
- Characteristics: The use of lead in these primers contributed to their durability, opacity, and hardness once dry. However, it also meant these materials were toxic.
- Drying Time: A significant drawback of this method was the extensive drying time required. Artists typically had to wait for approximately two weeks for the lead-based oil primer to cure sufficiently before the ground was stable enough to accept oil paint without issues.
Why the Shift to Modern Acrylic Gesso?
The evolution of art materials led to the development of acrylic gesso, a synthetic alternative that significantly streamlined the preparation process. Modern acrylic gesso offers a single, ready-to-use application that dries quickly, is non-toxic, and can be used on various surfaces for both oil and acrylic paints, eliminating the lengthy waiting periods and complex steps of traditional methods.
Comparison: Traditional Preparation vs. Modern Gesso
| Aspect | Before Acrylic Gesso (Traditional Method) | Modern Acrylic Gesso |
|---|---|---|
| Materials Used | Glue Sizing (e.g., Rabbit Skin Glue), Slow-Drying Lead-Based Oil Primer | Acrylic Polymer, Calcium Carbonate, Pigment (e.g., Titanium Dioxide) |
| Process Steps | Two-step (Sizing then Primer) | One-step (Direct application) |
| Application Time | Over two separate days | Single session |
| Drying/Curing Time | Up to two weeks for primer to cure | Minutes to hours |
| Toxicity | High (due to lead in primer) | Low/Non-toxic |
| Convenience | Labor-intensive, time-consuming, less flexible | Ready-to-use, quick, versatile |
| Primary Use | Primarily for oil painting on canvas/panels | For oil, acrylic, and other media on various surfaces |
This historical two-step process underscores the remarkable advancements in art materials, highlighting the convenience and efficiency that modern gesso brought to artists worldwide.
