Van Gogh self-portraits

Following on from the self-portraits of Gauguin, the second in my mini-series on self-portraiture logically features Vincent Van Gogh. For Vincent the self portrait was a more serious affair, not least for economic reasons. 
He painted over 30 self-portraits between the years 1886 and 1889. His collection of self-portraits places him among the most prolific self-portraitists of all time. Van Gogh used portrait painting as a method of introspection, a method to make money and a method of developing his skills as an artist.
As Van Gogh struggled to make a living as an artist he became reliant on his brother Theo and the charity of others such as Julien "Père" Tanguy, who ran the paint store that Van Gogh frequented in Paris. With their generosity of money and supplies, Van Gogh continued working as an artist and thought of portrait painting as a practical application of his talent. In a letter to his brother Theo in July of 1888 he wrote:
“Besides, I think I have spoken the truth, but if I should succeed in replacing in goods the money spent, I should only be doing my duty. And then, something practical I can do is portrait painting.”
In a letter to his brother Theo dated September 16, 1888, Van Gogh writes about a self-portrait he painted and dedicated to his friend and fellow artist Paul Gauguin: 
“The third picture this week is a portrait of myself, almost colourless, in ashen tones against a background of pale veronese green. I purposely bought a mirror good enough to enable me to work from my image in default of a model, because if I can manage to paint the colouring of my own head, which is not to be done without some difficulty, I shall likewise be able to paint the heads of other good souls, men and women.” (below)

In addition to Gauguin, Van Gogh also exchanged self-portraits with artist Émile Bernard. After receiving a letter from Bernard and Gauguin with their self-portraits enclosed, Van Gogh responded to Bernard encouraging portrait painting believing that portraits would always be in demand writing the following to Bernard:
“I strongly urge you to study portrait painting, do as many portraits as you can and don't flag. We must win the public over later on by means of the portrait; in my opinion it is the thing of the future.”