This 1740’s French Rococo gilt table is in the lab receiving treatment for an upcoming exhibition in 2021. The gold leaf surface is dirty and has an uneven varnish that, over time, has degraded and turned brown. When cleaning gilt surfaces there are two important things to keep in mind; the leaf is very thin and too much mechanical action can easily wear it away, and the method of leaf application will dictate what solvents can/cannot be used for cleaning. The gold leaf on this table was applied by water gilding. 

Due to this method of gilding, water cannot be used for cleaning as it will result in the removal of the gold leaf. Cleaning of the gilt surface begins with a light dusting to remove particulates that could scratch the delicate gold leaf. Next a wet cleaning with appropriate solvents is carried out to remove more stubborn soiling. Tests were carried out to identify whether the degraded coating could be removed.  Unfortunately it was found to be insoluble in any solvents that would be safe for cleaning this type of gilt surface and can only be slightly reduced.

Despite this, the appearance has been significantly improved with cleaning. As you can see in this photo, the extremely dirty cotton swab has removed a lot of discoloration caused by surface grime.