Sceau de Salomon. Convallaria multiflora L.

King Solomon's Seal or David's Harp, engraving by P.F. Le Grand after designs by the Dutch born Gerard van Spaendonck (1746-1822).
Taken from the rare work "Fleurs dessinées d'après nature. . . receuil utile aux amateurs, aux jeunes artistes, aux elèves des écoles centrales et aux dessinateurs des manufactures", containing 25 stipple engraved flower plates.
According to Nissen : "Copies are occasionally found either hand-colored or printed in color and retouched with watercolor. . . the watercolor serves in fact to cloak the delicacy of the stipple-work. In their black-and-white state, these prints may well claim to be the finest flower engravings ever made" (Great Flower Books).

In 1764 van Spaendonck was apprenticed to the decorative painter Guillaume-Jacques Herreyns, in Antwerp. In 1769, Gerard left for Paris and, having been appointed miniature painter to the newly crowned Louis XVI in 1774, he became a candidate for membership of the Académie Royale the following year, making his Salon début in 1777.
In 1780, he succeeded Madeleine Basseporte (1701–80) as professor of flower painting at the Jardin des Plantes. In 1781 he was elected a member of the Académie and began contributing to the Vélins du Roi, a series of botanical studies painted on vellum.

Gerard eventually contributed over 50 such studies (e.g. Hibiscus Flower , 1785, Paris, Mus. N. Hist. Nat.) and in doing so changed from the traditional medium of gouache to watercolor.
The task and the medium were assumed by his famous pupil, Pierre-Joseph Redouté. Van Spaendonck exhibited two of these flower studies on vellum together with five oils at the Salon of 1783 and was highly praised by the critics. At this period, he was also actively designing for the Sèvres porcelain factory.

Read more about Gerard van Spaendonck

Reference: Blunt, The Art of Botanical Illustration (L.: 1950). pp.175-176. Great Flower Books pp.21 & 77. Nissen BBI 1879. Stafleu & Cowan TL2 12.523.