Featuring Tilda Swinton as the voice of Scottish painter Wilhelmina Barns-Graham, this feature documentary tells the story of a remarkable artist and a magnificent obsession.

One day in 1949, young Scottish painter Wilhelmina Barns-Graham climbed a Swiss glacier. She was synaesthetic – associating letters, names and people with particular colours, and the experience transformed her art.

Featuring Tilda Swinton as the voice of modernist painter Barns-Graham, Mark Cousins’ latest feature documentary tells the story of a remarkable artist and represents a major reassessment of her life and work, and her place in 20th century art.