4. Presentation of the sheets of drawings
4.1 Usable surface area of sheets
On sheets containing drawings, the usable surface area may not exceed 26.2 cm x 17 cm. These sheets may not contain frames round the usable or used surface. The minimum margins are as follows: top side: 2.5 cm; left side: 2.5 cm; right side: 1.5 cm; bottom 1 cm.