Where does this come from, and can I check it?

ISO envelope series measurements allow flat A4 documents to slide in smoothly. The figure is taken from ISO, which is linked in full on this page. Every fact on Mondo Knows names its source rather than repeating an unsourced claim.

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Standard C4 envelopes are sized to fit flat A4 paper sheets

ISO envelope series measurements allow flat A4 documents to slide in smoothly

International envelope dimensions under ISO 269 use the C series geometric mean. A C4 envelope measures slightly larger than an A4 sheet of paper, allowing flat A4 documents to slide inside without folding. Similarly, a DL envelope fits an A4 page folded neatly into three equal sections.

Where this comes from

ISO

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Tags: paper, envelopes, standards

Standard C4 envelopes are sized to fit flat A4 paper sheets: the short answers

Where does this come from, and can I check it?: ISO envelope series measurements allow flat A4 documents to slide in smoothly. The figure is taken from ISO, which is linked in full on this page. Every fact on Mondo Knows names its source rather than repeating an unsourced claim.
Is this really a everyday life fact?: Yes. It sits on the Everyday Life shelf, one of 1,090 sourced facts grouped into space, animals, the human body, history, science and more. Category pages collect every fact in the same field.
What else can I read about it?: The links under the fact point to a quiz, game, puzzle or calculator on the same subject, and the shelf below shows related facts. The wording here is original, and quoted phrases are marked as quotations.