The studio was on the part of the convent between the cloister and Via del Maglio, [Footnote: Padre Marchese, _Memorie_, vol. ii. p. 69.] and we can quite picture its interior. There stands the lay figure on which Fra Bartolommeo draped the garments that take such majestic folds in his works; [Footnote: Fra Bartolommeo was the inventor of the jointed lay figure.] there are several casts and models in different parts of the room; grand cartoons in charcoal hang on the walls, like those we see to this day in the Uffizi and Belle Arti. So many of these masterly sketches are the Frate's and so few are Mariotto's that we may presume the former was in most instances the designer. And to what perfection he carried design! Not a figure was drawn except its lines harmonised with the geometric rhythm in the artist's mind. His groups fall by nature into kaleidoscopic figures of circles, triangles, ellipses, crosses, &c. Not a cartoon was sketched in which the lights and shadows were not as gradated and finished as a painting, although they were merely drawn with charcoal. The following was the method of work in the "bottega." The panels were prepared with a coating of plaster of Paris, over which, when dry, a coat of under colour, ground in oil, was passed. The preparing of the panels fell to the work of one of the monk scholars, Fra Andrea.[Footnote: The books of the convent have a note of payment to Fra Bartolommeo for 20th March, 1512, "per parte di lavoro di Fra Andrea converse per mettere d'oro, et ingessare alle tavole nella bottega in diversi lavori" (Padre Marchese, _Memorie_, lib. ii. chap. in. p. 70).] Then the master made his sketch in white, or "sgraffito" (i.e. graven on the plaster), as in the architectural lines of the pictures of patron saints in the Uffizi, and the _Marriage of S. Catherine_ in the Pitti Palace; he also put in the shadows in monochrome. But the assistants, who were skilled artists, were called to put broad level tints of local colour on the buildings, &c., the master himself finishing the faces. No doubt Albertinelli was often deputed to the study of the lay figure and its drapery. Where he assisted, the monogram, a cross with two rings and the joint names, marked the work, as en a panel of 1510 in Vienna, and another at Geneva.