色紙
しきし square fancy cardboard, used for autographs, poetry, etc.
Why it means this
色 (colour) + 紙 (paper) — a stiff square card for autographs or a poem, often gold- or silver-edged. Read しきし. (色紙 as いろがみ means coloured origami paper.)
Breakdown
Each character links to its full entry — origin story, stroke order, and readings.