A paperweight: a weight used to hold papers down so they don't blow away or shift.
窓を開けたまま書類が飛ばないように文鎮を置いた。
I put a paperweight on the documents so they wouldn't blow away with the window open.
書道では長い紙を押さえるために文鎮を使う。
In calligraphy, paperweights are used to hold down long sheets of paper.
この古い文鎮は骨董店で買ったものだ。
I bought this old paperweight at an antique shop.