in 1981, clarke was invited to teach as a visiting artist at pilchuck glass school in washington, with patrick reyntiens and dale chihuly, for the summer education programme. clarke introduced all-day life-drawing classes, intensively teaching academic drawing from the life in place of glass painting techniques with the aim of opening up 'new ways of looking at glass design'. later that year, receiving a commission from the government of saudi arabia for the royal mosque of king khalid international airport, clarke studied islamic ornament at the quran schools in fez. a portfolio of screenprints, dedicated to his friend c. p. snow called '"the two cultures"' (after lord snow's influential 1959 rede lecture on the perceived gulf between the humanities and sciences of the same name) was published, and he became the first artist to have an exhibition at the royal institute of british architects, with a solo show of his paintings, constructions and prints. that year, the first monograph on his work, "brian clarke" by martin harrison, was published, and the victoria and albert museum acquired a large-scale stained glass triptych, executed by him in 1979, and an oil painting titled "trial and error". the royal mosque, completed in 1982 and containing 2,000 square metres of stained glass, was considered to be the largest and technically most advanced stained glass project of the modern period, requiring the full staff of 4 stained glass factories and 150 craftsmen, taking a year to fabricate. urged by his art dealer robert fraser to leave britain to avoid the gossip columns and paparazzi, clarke moved to live and work in düsseldorf and rome.