SIS E5

The SIS E5 paper size measures 155 mm x 220 mm, defining a surface area of about 0.034 square meters. Sandwiched incrementally between SIS E4 and ISO A4, it is one of the few Swedish extensions to see some usage despite minimal adoption overall.

Besides its metric measurements, the niche SIS E5 format is occasionally referred to as "lilla E fem" meaning little E five in Swedish.

The E5 enjoys some popularity in Sweden and the Netherlands as a format for printing academic dissertations. This application leverages its dimensions falling roughly between A4 and A5. Beyond this niche usage however, SIS E5 has limited relevance.

The SIS E5 emerged alongside other Swedish size extensions in a failed attempt to systematically interpolate intermediate options between ISO's entrenched A, B and C formats. The goal was to enable subtle scaling of document contents across sheet sizes. But manufacturing considerations, lack of global standardization, and the self-perpetuating nature of norms undermined this. So SIS E5 continues to occupy a largely unused, obscure position except for its specialized role with certain dissertations. Its backstory reflects the power of path dependence and switching costs that reinforce standards.