A single thickness of a split hide.
皮厚一层被剥下的皮的厚度
A unit of length equal to one thousandth(10-3) of an inch(0.0254 millimeter), used, for example, to specify the diameter of wire or the thickness of materials sold in sheets.
密耳长度单位, 等于一英寸的千分之一(10-3)(0。0254毫米), 如用来标明电线的直径或按页出售的材料的厚度
As a result, nacre thickness is sometimes just a cosmetic layer that can wear thin over time.
所以真珠质的厚度就像脸上化妆品, 不久就会磨薄了。