Janes created three portraits of Thomas. The first, painted in Coleherne Road in 1934, is oil on canvas, displaying Janes's technique at this period of cutting lines into the paint with his pen-knife, to provide relief and focus. When Janes decided in 1936 to return to Swansea, he left his accumulated works behind and most are now lost; but the portrait of Dylan Thomas and some other paintings and drawings had been acquired by Cedric Morris and Augustus John, to form part of an exhibition of Welsh artists held in Cardiff, and the portrait was purchased in 1935 by the National Museum Cardiff. Later Janes "...complicated the technique by marking a polygonal grid on to the board before painting the subject, and then retracing and incising it into the finished painting. In this way he was able to achieve a unique crystalline brilliance of image." The second portrait of Thomas is held by Swansea University. Janes's last portrait of Thomas is pen and ink on paper, drawn around 1964, a decade after the poet's death; it forms part of the permanent collection of the Glynn Vivian Art Gallery, Swansea.