Jan van Os was born in Middelharnis. He was taught by Aert Schouman in The Hague, where he would spend the rest of his life.
In 1773, he became a member of the painters’ club Pictura. Two years later, he married the deaf-mute pen portraitist Susanna de La Croix, daughter of the French portraitist Pierre Frédéric de La Croix (1709–82), also a deaf-mute. Although van Os started his career with paintings of seascapes in the manner of Jan van de Cappelle and Willem van de Velde II—a genre that he continued to employ throughout his life—he was most famous for his asymmetrically composed pyramidal still-lifes of fruit and flowers in the manner of Jan van Huysum. These are set, like those of van Huysum, on a marble ledge, often with a terracotta vase, against a pale green landscape background. Van Os acquired an international reputation for his still-lifes: his work was valued highly both in England, where he exhibited at the Society of Arts in London from 1773 to 1791, and in France and Germany.
He was the father of artists Pieter van Os, Maria Margaretha van Os, and Georgius Jacobus Johannes van Os and grandfather to the painter Pieter Frederik van Os.
Shipping in a Calm is a lovely painting by van Os done in the marine genre with which he began his career. In the rosy glow of morning, several ships dock themselves near a vaguely suggested shore. Men are at work bringing down sails. One man in a lifeboat rows toward the land, while to his right two seabirds skim low over the perfectly calm sea. In the hazy distance, the viewer can see several more ships that are perhaps also coming in to dock. Van Os’ brushwork is delicate and precise; this wonderful work truly shows off the artist’s masterful skills.