In the 1950s Middleditch devoted himself mainly to painting natural themes. His work over the following decades concentrated chiefly on the elements: from the weight of a huge hillside to the lightness of sunshine on water or darting through foliage. Inspired by kilims and Persian carpets, his work became increasingly abstract and stylised. He also used stencilling to create decorative patterns.
In 1973 Middleditch was elected a member of the Royal Academy and from 1984-1986 he held the post of Keeper of the Royal Academy, in charge of the Schools.
