Classic Art Online is a theme auction, presenting a curated selection of high-quality classic art. Plein-air painting make up a dominant portion, with graphic works, but also sculpture and prints are included. The 19th century and the turn of the 20th century were periods marked by industrialization, modernity, and scientific advancements, which provided new opportunities for artists. The pre-mixed paint in tubes was an innovation, enabling artists to venture beyond their studios and art schools with greater freedom.
 
During the 1860s, artists in Paris began taking their easels and brushes outdoors to paint what they observed, a practice known as 'en plein air.' This French tradition of plein-air painting rapidly spread throughout Europe and the United States during the following decades, fundamentally reshaping Western art. In this auction, Swedish plein-air painting is well-represented, featuring works by artists such as Oskar Bergman, Otto Hesselbom, Anshelm Schultzberg, and Wilhelm von Gegerfelt. Additionally, the sale includes figure scenes and portraits by artists like Anders Zorn, Jenny Nyström, and Carl Wilhelmson, as well as animal paintings by Mosse Stoopendaal and Thure Wallner. Apart from the selection of Swedish art, there is a high-quality international section featuring paintings by artists such as Hans Hilsöe, Auguste Emile Pinchart, and John Crealock.