The Paintings conservator is responsible for the care of more than 380 paintings in the Winterthur collection, as well as their frames and painted surfaces on objects such as furniture and clock dials. Paintings conservators address structural problems such as torn or deteriorated canvas or stretchers that cause distortion and loss of the paints and varnishes applied to them. Paint on any substrate (canvas, wood, or metal) may begin to flake due to physical damage, corrosion, or shrinking and swelling in the substrate caused by unstable relative humidity. Wood and fabrics such as canvas absorb and release moisture as the relative humidity fluctuates, which results in dimensional changes. Because the paint layer absorbs moisture at a different rate, it cannot change with the substrate, causing the paint to flake. Varnishes and coatings applied to the surface age and darken with time and may require cleaning or removal and replacement.

Visually and structurally, frames are an integral part of paintings because they provide protection and the means to hang a painting. Traditional frames are composed of wood, compo (a plaster-like mixture of chalk, glue, resin, and oil) and various gilt and painted finishes that are subject to abrasion and physical damage that causes breakage and loss of decorative elements.

Preventive Conservation

Like other parts of Winterthur’s collection, paintings are maintained at a stable temperature and relative humidity of 50 percent and protected from excessive light that can accelerate aging of varnish and fading of pigments. Proper framing requires a backing board to protect the canvas and secure hardware to ensure safe hanging.