At the age of twenty he became an assistant to Andrew Robertson (1777–1845), the eminent Scottish miniature-painter, and, although his first ambition was to excel in historical painting, he thought it advisable to concentrate on the more lucrative speciality of miniature-painting. He soon acquired a sizeable and elite clientele.
At twenty, he became an apprentice to Andrew Robertson (1777–1845), a celebrated Scottish painter of small-scale artworks, and although his initial ambition was to master historical painting, he thought it wise to concentrate on the more profitable art form of miniature-painting. He quickly built up a prestigious client base.