Chalk black, red and white chalk on faded blue paper, upper corners made up
21 cm - 14.5 cm (8.27 in - 5.71 in)
Chalk coloured chalks on blue prepared paper, minor losses
22.5 cm - 15.8 cm (8.86 in - 6.22 in)
Chalk black and white chalk on blue gray paper
18.3 cm - 12.8 cm (7.2 in - 5.04 in)