Typical steps in restoring a painting
It’s important to remember that each restoration will be different as each art work has different requirements.

Generally, painting restoration consists of the following steps:

Surface dirt removal - Dust and dirt has a tendency to collect on the backs of paintings, settling between the canvas and stretcher bars, and becoming engrained in the exposed canvas. Dirt can be removed by the gentle brushing or vacuuming of dirt to clear particles on the surface of the painting before removing the varnish.

Varnish removal - Varnish may become very yellow over time. This discolouration will alter the tonal balance within the painting, making it look significantly different from how the artist intended. Varnish removal or a similar solvent can be used to remove the discoloured varnish layer.

Structural treatments - A canvas support may also be damaged structurally in the form of tears, holes or punctures. Thread by thread
reweaving of the tear may be possible in certain cases. Where individual threads are lost or no longer join together, threads may be taken from the canvas edge or a new or degraded fabric with a similar thread type and thickness can be used. Fabric inlays may be required when there is a hole in the canvas.

Retouching - Sometimes layers of paint are removed or lost so retouching is undertaken, which involves applying paint to fill the defective areas using pigments to match the original paint exactly. Small brushes and fine brushstrokes are used to fill in the missing spaces.