Mackey trained at the Slade before the First World War, in which he served with the Royal Army Medical Corps on the Western Front, as an Official War Artist. After the war he worked principally as a book illustrator and printmaker, but he also exhibited paintings in France and from the 1930s taught at Walthamstow School of Art.

Mackey’s print work consisted of coloured linocuts and woodcuts. For his colour prints he devised his own technique, whereby the block was printed on thin see-through paper similar to tracing paper, in black ink, though sometimes with a second colour. The rest of the colours were achieved by hand-painting in oil colour on the reverse and when dry, sticking the impression, paint side down, onto an oatmeal support sheet. The double sheet was trimmed to appear as one.

Mackey’s prints are rare, as they were never formally editioned, no doubt due to the complexity of their production.