Doing preliminary drawings before working on the final image allows the artist to get a feel for the dimensions of the chair and the best points to start the final from. These practice drawings also help to understand that even though we are working with still life art the models used are effected by the day to day activity in the studio causing changes in the placement and shape of our chosen chair. We must be able to adapt our art as the model changes till we have the final form with shadows down and no longer need the model.
The thumbnail drawings allow for us to plan different ways to draw the same chair. Be it different shading technics, close-ups, or even duplicating the same object in one drawing. Two of my thumbnail drawings are the complete chair with one tilting more towards the right and farther down the page. One is a close-up of the chairs leg peeking from under the cloth. The last drawing is the one I chose for the final drawing; The image shows the whole chair floating with the excess cloth dragging/falling on the ground.