17 CFR 260.7a-17: a-17 Quality, color and size of paper.

The application, statement or report, including all amendments and, where practicable, all papers and documents filed as a part thereof, shall be on good quality, unglazed, white paper, no larger than 8 1/2 × 11 inches in size. To the extent that the reduction of larger documents would render them illegible, such documents may be filed on paper larger than 8 1/2 × 11 inches in size.