Since the 16th century, the Netherlands has a large number of very good art painters. The average quality of landscapes, still lifes and portraits is high. In the 16th century, the oil paint was still made by the painters or their pupils. Coloring pigments were then rubbed in oil. In the 19th century, the artistic paints produced by industry came together, with the consequent “competition”, which meant that quality was not always the best. It was also found afterwards that a newly discovered, chemically-made color was not color-resistant in the long run. Examples of these include paintings by Vincent van Gogh. In the 20th century, the Acrylic paints have been added. These are color pigments dissolved in a plastic dispersion and water soluble.
I have experience in all of these paintings, in terms of cleaning and the possibilities for repair / restoration.