Individual male models opinions will vary on this subject. One point of view is it is not a question of “if” an erection will occur during the 3 or 4 hour drawing session, but “when” . The model may take a break if this happens and it is not a problem. In some cases the model may asked to hold the pose to include his erect penis in the drawings. In private workshops if arrangements are made in advance the selection of a model comfortable posing in an aroused state is preferred.