folding book
A book made of folded sheets, often used for traditional calligraphy or painting albums.
Old waka poems are written in this folding book.
counter for units of paper and nori
Traditional counter for paper and nori: 1 帖 = 48 sheets of Mino paper, 20 sheets of hanshi, or 10 sheets of nori. Rare in modern daily life.
Please give me one unit (48 sheets) of Mino paper.
counter for pairs of curtains
Counts pairs of curtains; one 帖 is a pair. Specialized usage.
This room has three pairs of curtains hanging.
counter for tatami mats
Commonly used to count tatami mats and express room size. Often written as 畳, but 帖 is also used.
See also: 畳 (じょう)
This room is six tatami mats in size.
I bought one 帖 (48 sheets) of Mino paper.
My grandfather's house has a two-panel folding screen.
I live in a six-tatami-mat room.
畳 is the traditional, general-purpose counter for tatami mats, while 帖 is the same reading and meaning but used mainly in real estate listings.
The kanji 帖 originally referred to a folded document or book, and its counter uses derive from counting folded or sheet-like items. The tatami-mat counter sense is an extension of counting flat, sheet-like objects.