<P> Because he was painting fresco , the plaster was laid in a new section every day , called a giornata . At the beginning of each session , the edges would be scraped away and a new area laid down . The edges between giornate remain slightly visible ; thus , they give a good idea of how the work progressed . It was customary for fresco painters to use a full - sized detailed drawing , a cartoon , to transfer a design onto a plaster surface -- many frescoes show little holes made with a stiletto , outlining the figures . Here Michelangelo broke with convention ; once confident the intonaco had been well applied , he drew directly onto the ceiling . His energetic sweeping outlines can be seen scraped into some of the surfaces , while on others a grid is evident , indicating that he enlarged directly onto the ceiling from a small drawing . </P>
<P> Because he was painting fresco , the plaster was laid in a new section every day , called a giornata . At the beginning of each session , the edges would be scraped away and a new area laid down . The edges between giornate remain slightly visible ; thus , they give a good idea of how the work progressed . It was customary for fresco painters to use a full - sized detailed drawing , a cartoon , to transfer a design onto a plaster surface -- many frescoes show little holes made with a stiletto , outlining the figures . Here Michelangelo broke with convention ; once confident the intonaco had been well applied , he drew directly onto the ceiling . His energetic sweeping outlines can be seen scraped into some of the surfaces , while on others a grid is evident , indicating that he enlarged directly onto the ceiling from a small drawing . </P>
the medium of the artwork that decorates the sistine chapel ceiling is
the medium of the artwork that decorates the sistine chapel ceiling is
fresco
fresco