這絕對可以做到,只是藏得比較深!系統內建了幾種預設的浮水印 PDF,您也可以製作自訂的 PDF 並套用。
順帶一提,下次當您尋找某個設定時,請試試對話框底部的「Search for settings」(搜尋設定)工具:

點選其中一個選項,就會直接帶您到該設定並為您標記出來。
That’s certainly possible, but well hidden! There are a few default watermark PDFs included, or you can make a custom PDF and apply that.
By the way, the next time you are looking for a setting, try the “Search for settings” tool at the bottom of the dialog:

Selecting one of those options till take you straight to the setting and highlight it for you.
機器翻譯自 English