PA6

With dimensions of 105mm x 140mm, the PA6 format has a total surface area of 0.0147 square meters. As part of the transitional PA paper size series originally proposed in 1975, PA6 falls between the PA5 and A6 sizes. Its orientation is more of a squat version of A6, while maintaining the efficient 1:√2 aspect ratio common across the PA system for easy scaling. PA6 does not have any widely used alternative names. Typical applications include postcards, fliers, and compact booklets where the slightly shorter height compared to A5 provides some minor horizontal space savings. Since the PA series aimed to fill gaps left by the limited number of ISO 216 standard sizes, PA6 was conceived solely as a transitional step between PA5 and A6 without much unique history of its own. After rejection along with the rest of the PA formats for official inclusion in the standards, PA6 continues fulfilling a niche role for use cases where A6 on its own is just slightly too tall. Though it lacks a colorful backstory, PA6 persists in serving the intended role of adding grades between standardized sizes, in this case an extra grade of horizontal space between PA5 and A6.