%% on veut obtenir une Bouding Box de 0 0 842 576 (format A4r)

28.4527 setxunit %% 10 mm
-.271 19.271 setyrange
-.446 28.446 setxrange
10 setborder

[5 5] {.4 setgray} Quadrillage

0 19 setyrange
0 28 setxrange
[1 1 .5 .5 .1 .1] {.4 setgray} Quadrillage