unsized paper
Paper that has not been treated with sizing (a substance that reduces absorbency). A technical term used in papermaking and calligraphy.
Unsized paper bleeds easily, so it is suitable for calligraphy practice.
Compound of 生 (ki, 'pure, raw') and 紙 (kami, 'paper'), with rendaku voicing of kami to gami. The exact historical derivation is uncertain, but the term directly describes paper in its untreated state.