How do you apply gold leaf to gesso?

Applying gold leaf to gesso involves several steps to ensure a professional and lasting finish. Here's a breakdown of the process:

1. Prepare the Surface with Gesso: Ensure the object you're gilding is properly primed with gesso. This creates a smooth, slightly absorbent surface for the subsequent layers. The gesso provides a foundation for the gold leaf to adhere to.

2. Apply a Base Coat (Optional but Recommended): While not strictly necessary, painting a dark-colored acrylic or metal leaf base coat onto the gesso can enhance the appearance of the gold leaf. This is because true gold leaf is very thin, and any imperfections or the color of the gesso underneath can show through. A traditional color is red bole, but you can also use black, umber, or other dark colors to create different effects.

3. Apply the Gold Size (Adhesive): Use a specialized adhesive called "gold size" or "gilding adhesive." This comes in different drying times (oil-based size offers longer open time). Apply the size with a soft brush (¾" or 1" recommended). Ensure an even, thin coat. The size needs to become tacky before applying the gold leaf. Follow the manufacturer's instructions for drying times, as they vary.

4. Apply the Gold Leaf: Once the gold size is tacky (not wet), carefully apply the gold leaf. This is delicate work. You can use a gilder's tip (a flat brush designed to pick up gold leaf) or carefully transfer the leaf with your fingers (wear gloves to avoid oils). Overlap the edges of the gold leaf sheets slightly to ensure full coverage.

5. Burnish or Pat the Gold Leaf: After the gold leaf is applied, gently burnish or pat it down with a soft brush or cotton ball. This helps the leaf adhere to the gold size and removes any excess flakes. Burnishing tools can be used if the gold size allows (check manufacturer's instructions). Be careful not to scratch the gold leaf.

6. Clean Up and Remove Excess Gold: Use a soft brush (a gilder's mop is ideal) to gently sweep away any loose pieces of gold leaf. These scraps can be saved for patching small areas or other projects.

7. Apply a Protective Varnish (Optional but Recommended): To protect the gold leaf from tarnish and abrasion, apply a thin coat of varnish specifically designed for gilded surfaces. Use a high-quality varnish that won't yellow over time. Apply the varnish in thin, even coats, allowing each coat to dry completely before applying the next. This step is particularly important if the gilded object will be handled or exposed to the elements.

In summary, successful gold leaf application to gesso depends on careful surface preparation, selecting the right adhesive, meticulous application, and proper finishing.