Launched in April 2017, PaperSizes is a side project by UK Designer Rob Lafratta and developer Richard Franklin, who in their spare time wanted to create a tool for themselves and for others who needed quick access to paper sizes.
All type is rendered in two weights from Work Sans, a typeface family designed by Wei Huang and released under the SIL Open Font License in 2015.
This website makes it much easier to find this information than it is elsewhere. The grid, the grotesque font and the ragged-right column compose a reference to the international style, which is apt for such a topic as international weights and measures. The boxes on the top half of the website are unrelated, though, and thus it mixes design languages, and not unsuccessfully.
While in a high-contrast serifed font we might have wished that the larger text be in a larger optical size, evening out the stroke width (at its thinnest), here the bolder appearance of the regular weight at a larger size serves only to aid its display function. The consistency also helps the site seem more “minimalist”, but it does use the bold weight for table headings.