Japanese paper; washi
Refers to traditional Japanese paper, often handmade. The term 和紙 is more common in everyday use.
See also: 和紙
I made a lantern out of Japanese paper.
Japanese paper, also called washi, is made using traditional methods.
洋紙 refers to Western-style machine-made paper, contrasting with the traditional handmade 日本紙.
Used because 日本紙 (Japanese paper) is thin, and flat thin things are naturally counted with 枚.
Compound of 日本 (Japan) and 紙 (paper). The reading にほんし follows standard on'yomi for both kanji.