underpainting / ˈʌn dərˌpeɪn tɪŋ /

⚽高中词汇底漆打底画底层绘画打底漆

underpainting 的定义

n. 名词 noun
  1. the first coat of paint, especially the initial painting on a canvas in which the major areas, tones, colors, and forms are indicated in mass.