3. Requirements regarding the paper used 

If the international application is filed on paper, drawings must be on sheets of A4 paper (29.7 cm x 21 cm), which must be flexible, strong, white, smooth, non-shiny and durable. The sheets must be free from creases and cracks; they must not be folded. Only one side of each sheet may be used.

Under Rule 11.12, each sheet must be reasonably free from erasures and must be free from alterations, overwriting and interlineations. Non-compliance with this rule may be authorised if the authenticity of the content is not in question and the requirements for good reproduction are not in jeopardy.