I was surprised to see the word ‘patina’ appear as a Daily Prompt today. It’s a very ‘conservation’ sort of a word and one that is pretty loaded. It refers to the quality that something acquires as it ages, a sort of ‘lived in’, mellow look. When that’s an oil painting it means dusty and yellow. One of the major criticisms of conservation is that we strip away patina when we clean pictures or other works of art, and take with it something that made the work of art feel more special or authentic. As I’ve previously talked about, one of the best ways to ensure that you’re not taking off something you shouldn’t is to work in a controlled way tackling surface coatings in layers rather than all at once.
My own criteria for deciding whether or not to remove a coating, and I’m sure I’m not alone, depends very much on originality. If a varnish is present that I believe to be original, which is rare, especially in museum collections, then my default position is to leave it where it is. There are a number of things that might alert you to an original varnish including the known history of the object and uneven or selective varnish application. It’s important to consider whether or not a varnish has been applied by the artist as if that is the case it has likely been applied closer to the time that the painting was finished, so may have bonded with the fresh paint beneath, making the distinction between paint layer and varnish layer blurry. The artist may also have decided to add finishing touches on top. Turner was renowned for varnishing his pictures before the paint was dry. There has also been much discussion about how much artists may have anticipated and hoped for the effects of age on their varnishes.
Dirt, for me, is less of a problem. Unless there was some kind of hugely important event that caused the dirt, it’s not usually considered to be significant to the history of the object. One item that I can think of that would fit into this category is Jackie Kennedy’s outfit worn in Dallas on the day of her husband’s assassination, which is in the collection of America’s National Archive still gruesomely soiled. It would obviously be entirely inappropriate to clean the suit but it’s significance also renders it undisplayable. Thankfully the dirt on paintings is usually far more innocuous but if left on the surface it robs the picture of depth and vibrancy, eventually making the paintings illegible and unfit for display.