The final plat shall be legibly drawn in waterproof ink on mylar or other material of equal performance. It shall be drawn at a scale not less than 100 feet to the inch, and shall be one or more sheets eighteen inches by twenty-four inches in size. If more than one sheet is needed, each sheet shall be numbered and the relation of one sheet to another clearly shown. If more than five sheets are required, a master composite sheet at a smaller scale as an index shall be provided.