 Etty generally finished life studies during three evenings sittings . On the first evening he would sketch the model in charcoal or chalk , and then ink in the outline . On the second he used oil paints to fill in the figures . On the third he layered glaze and the final coverings of paint . He usually painted on millboard , re @-@ using the reverse for fresh paintings . His female models were typically shop @-@ girls , prostitutes , actresses or poses plastiques models , while his male models tended to be Life Guards recruited from the nearby barracks , who he thought to have an appropriate muscular physique , or occasionally men Etty met in public bath houses . 
