'A painter of severely simplified figures in heavy black outlines combined with areas of yellow ochre and blue. Robertshaw transforms the figure in a powerful manner, making it function as an abstract form. He is a painter well worth watching in the years to come...' Richard Fuller, Art Speak New York - April 1997

As a child Robertshaw emigrated with his family from South Africa settling in the Hawkes Bay. He attended Victoria University from 1970-1973 and began painting in 1981. Working primarily in acrylic and multimedia he describes his work as spontaneous and emotive.

Paintings from the mid 1990's such as the Te Mata Series featured works of reclining abstract figures. These large works captured Robertshaw's vision of the New Zealand landscape with undulating figure forms representing the rolling hills of Hawkes Bay.

By the late 1990s and early 2000's Robertshaw departures from figurative works with the result of Bay and Marine Series, works inspired by New Zealand's involvement in the Americas Cup. One of Robertshaw's paintings from the Marine Series was chosen as the banner masthead for New Yorks Fleet Week, a large event when the United States naval fleet berths in New York.

Robertshaw continues to change and evolve as an artist and 2002. 2003 saw the emergence of architectural paintings inspired by the art deco movement in Napier and more recently the equine paintings of the Animus Series.

Since 1984 Robertshaw has exhibited in Berlin, Australia and New York. Two of his works have been purchased for the collection of the Robert Mapplethorpe Foundation, New York.