Callum studied Drawing at Camberwell College of Arts before relocating to Leeds, where a growing art scene and affordable studio space allowed him to scale up his practice. He works almost entirely in charcoal on heavyweight cotton rag paper, building tonal masses slowly before refining with erasure and blending. His subjects are drawn from extended sittings with people he knows well, the resulting portraits have an intimacy and specificity that sets them apart from more generalised figurative work. Callum has exhibited at the National Portrait Gallery's BP Portrait Award, the Lynn Painter-Stainer Prize, and several North of England galleries.