In the begining of his carreer, Van Gogh did a lot of drawings. He draw his father, people doing their daily work in the fields, Sien the prostitute who lived with him for over a year.
In the letters he wrote to his brother Theo, Vincent Van Gogh used to draw some sketches of his actual projects.
He would explain in his letters the intention of the colours and techniques he was going to use. In his drawings, is shown an accurate hand for the proportions of the figures and their characterization.
In the drawing of Sien pregnant sitting in the floor with a cigar in the hand is a very unique motif, drawn with great sensitivity.
Many expert consider that this drawings and sketches are as genius as the final masterpieces, most of this letters are kept in museums as art pieces.