paper, label, letter, composition
箋 centers on a piece of writing material: a slip of paper, a label, a letter, or a short written composition. The common thread is a bounded, often rectangular, surface for writing.
箋 combines 竹 (bamboo) with 戔, which likely contributes the sound. Bamboo was historically used for writing slips, so the character suggests a bamboo writing tablet or label.
The top 竹 (bamboo) suggests a material for writing, and the bottom 戔 looks like a stack of papers or a label with marks. Picture a bamboo slip used as a label or for a short letter.
For セン, imagine writing a label with a pen: pen -> セン, and the bamboo slip becomes your paper.
prescription
sticky note; tag; slip; label; Post-it note
writing paper; stationery; notepaper
slip (of paper)
small notepad
sticky paper slip; sticky note
prescription drug; prescription medication
letter paper
stationery; writing pad
prescription
commentary on the Book of Odes by Zheng Xuan