As Jaimy Tan explains, the "material" refers to the jade itself. Professional carvers apply their "workmanship" to shape the jade into a "form" that will exploit the natural "contours" of color and shading of the material.
譚白絹解釋，所謂的「料」是指玉石本身，專業的工匠會「因料施工」來雕琢玉「形」，讓最美麗的天然紋路自然顯露。