A thin flat sheet with shapes cut out of it, pressed against a surface. Colour can only get through the holes, so the sheet decides the edges and your hand does not. Lift it, and the shape is there — the same shape, as many times as you like.
The supplied source traces the noun to Middle English stencellen 'to garnish with bright hues', from Old French estenceler 'to spark', ultimately Latin scintilla 'spark'. The oldest idea is putting bright colour onto something; the cut-out sheet came later and narrowed it.
packet 裡的來源說這個名詞很可能出自中古英語 stencellen「用鮮亮的顏色裝飾」，再往前是古法文 estenceler「使閃爍」，最早是拉丁文 scintilla「火花」。所以最原始的想法是「把亮色點上去」，鏤空板子是後來才把這個意思收窄的。來源同時指出，動詞是從名詞長出來的。
Wiktionary entry supplied in this packet (source_ref kaikki:3f6f69a190036ae4:1165807936): "Likely a nominalization of Middle English stencellen … from Latin scintilla ("spark"). The verb is from the noun."
Two branches
板子與動作
核心畫面的兩個部分：手上的工具，以及用它的那套動作。
noun · B2
A thin sheet of plastic, metal, or card with shapes or letters cut out of it. You hold it flat against a surface and paint or spray over it, so colour reaches the surface only through the cut-out parts.
鏤空模板
板子拿開之後
鏡頭停在同一個畫面的最後一秒：板子已經拿走，留下來的痕跡接手了這個名字。
noun · C1
The pattern, letters, or picture that is left on a surface after paint has been put through a stencil.
模板印出的圖