Out of the turbulence of the years after his divorce Thubron produced comparatively few works of art, but these, based on a dialogue between old and new materials, and painting and collage, were treasured by friends and colleagues who rightly judged them to be sensitive and beautiful.
With Dennis Harland as technical adviser he produced a fine relief in plastics for the exterior of the Branch College, Leeds (1963–4; removed), which fulfilled his ambition to make art for public, architectural settings.
Thubron's wartime experience of teaching soldiers via the text of the Army Council of Current Affairs Newsletter gave him a vision of a "new post-war world" and the rhetoric to achieve it.
While teaching at Sunderland School of Art from 1946, he began to elaborate new courses (from 1948 onward), contributing (from 1954) to those directed by John Wood of North Riding county council, which allowed for greater innovation.
Pasmore had worked at the Central School of Arts and Crafts, London, on the basic design course, instigated in 1949 with William Johnstone and Arthur Halliwell.
These chosen phrases gave expression to his perception of rapid contemporary changes in technology and society, and he rejected the label "basic design" which he thought was given too freely to radical modernist teaching.
While he is remembered for his warm personality and vivid use of the spoken word, an extensive documentary record of his work as a teacher is held in the National Art Archive, Bretton Hall, Yorkshire.
During his ten-year tenure in Leeds he helped to revolutionise art education in England by establishing the Basic Design Course, a programme inspired by the German Bauhaus college and the theoretical writings of Herbert Read.
Out of this, and similar experiments undertaken by Victor Pasmore and Richard Hamilton at Kings College Newcastle, a new introductory course for art, design and architecture students emerged, called the Foundation Course,[7] which went on to become the standard degree course-entry qualification for art, design and architecture students in many countries, including Britain, Ireland, Canada and elsewhere.
Thubron also organised by this time a series of "summer schools" in Yorkshire and Norfolk, in which he shared his ideas on art education with teachers, students and artists who came from all over the country, markedly influencing an entire generation of creators as Hoyland, Sausmarez, Bridget Riley and Michael Kidner.
They experimented, for example, with families of forms whereby a square could by repeated modification become an oval; or, given a blob of red paint, a student would be directed to mix and place next to it on the paper what he or she perceived to be the most enhancing green.