His work focuses on the rural working class. Pieces like Rustic Figures: Two Boys and Seated Man with Baskets show his interest in everyday life. Barker drew from nature and used charcoal or chalk to capture the textures of worn clothing and rough tools. His prints often retain the loose, gestural quality of a sketch. This approach gives his depictions of shepherds and tilemakers a sense of honesty. He preferred the quiet observation of a Halt at the Spring over dramatic or historical subjects.

Modern collectors value these prints for their muted colour palettes and textural depth. The lithographic process creates soft, grainy lines that resemble original drawings. These works provide a window into the rural past without the stiff formality of traditional portraiture. They work well in contemporary spaces because of their simple compositions and earthy tones. Barker's focus on the individual character of his subjects makes each print feel personal.