Sometimes conservation is a matter of weight and see! Here is a detail from a Retablo of Saint Peter panel that is flat on a table. The painting is tempera and gold leaf on wood panel and there is a lot of flaking paint and gilding that is being consolidated. In the consolidation process, a liquid conservation adhesive is brushed under the raised flakes and through open cracks in the painting. While the adhesive dries, the area is often weighted to improve the bond between the lifting paint and the surface below. A typical application of weight is shown here. First, a layer of Mylar film is laid on the consolidated area. The Mylar protects the paint surface from scratching or rubbing, and it’s coated with silicon so that it won’t stick to the painting if any of the adhesive comes into contact with it. On top of the Mylar is a small thin steel plate, just visible. The plate provides even contact and distribution of the weight that is placed on it. This particular area of flaking, on the enthroned Saint Peter’s face, required rather a lot of weight. Thus a dense iron weight from an old scale (a flea market find!) has been put in on the steel plate. As you can see, the 4” diameter weight is a solid two pounds. Such a heavy weight would not be used on most paintings, those on canvas or with raised brushstrokes of paint, for example, but here it provides the pressure needed to conserve the Retablo’s flaking paint and gilding. Weights are usually left in place overnight or longer depending on the adhesive. When the weight, steel plate and Mylar are removed, the paint and gold leaf will be securely adhered and in plane with the surface of the painting.

Image Credit: Lorenzo Zaragoza (circa 1340–circa 1410), Spain, Retablo of Saint Peter, circa 1400, tempera, gold and silver on wood. The Edwin and Virginia Irwin Memorial 1960.473