Douglas Percy Bliss (1900-1984) was a painter and engraver. He was part of the group of artists associated with Eric Ravilious and Paul Nash, and was the director of the Glasgow School of Art from 1946-64.
He first visited Barra in 1927, producing a number of paintings and wood engravings. He returned at later dates, producing a series of paintings around 1934-7
Here’s his account of the 1927 trip: