As the Modern movement gained recognition in New Zealand in the late 1930s, Woollaston emerged as its most uncompromising exponent. His paintings ignored traditionally grand views of the landscape and his portraits disregarded social and flattering conventions. Although he struggled economically while living in Greymouth on the West Coast of New Zealand's South Island (1949-68), his expressive, visionary work thrived and by 1963 he was painting fulltime. In 1979, he became the first New Zealander knighted for services to the arts.
Woollaston has works in the permanent collections of all the main public art museums in New Zealand.