Fetching details from the dictionary...

paper patch attached to something; paper backing; sticker; label
notice; poster
窓に張り紙があった。
There was a notice on the window.
壁に「禁煙」と書かれた張り紙が貼ってあった。
There was a poster on the wall that said 'No Smoking'.
ドアに張り紙をして注意を促した。
I put a paper sign on the door to alert people.