I am currently working on the painting below by Nicolaas Pieneman, 1835. The piece is untitled, but the provence states it was commission by William of Orange and given as a gift to my client's grandfather. This painting is in excellent condition without tears or punctures. The surface was 'varnished' with linseed oil, which hardens and darkens over time. Fortunately, this painting had a thin layer that is removing slowly. Thicker coatings of linseed oil can be very difficult to remove.