For Mona Lisa, he used a thin-grained piece of poplar tree and applied an undercoat of lead, white.

《蒙娜丽莎》时，他使用了一棵纹理很薄白杨树，并涂了一层白色铅底漆。

It consists of two layers of transparent hair, a soft thick undercoat and a layer of hollow guard hairs.

它有两层透明皮毛，一层是柔软厚实皮毛，一层是中空护毛。

He then applied a series of undercoats, letting them dry before applying another.

然后，他涂了一系列底漆，等它们干了再涂一层。

But for many mammals, hair grows in two layers consisting of a shorter undercoat of ground hairs covered by longer guard hairs.

许多哺乳动物毛发生长为两层，由毛为底层毛发，上面覆盖长保护毛。

The lead white undercoat reflects the light back through his glazes, giving the picture more depth, and in essence, lighting Mona Lisa from within.

铅白色底漆将光线通过釉料反射回来，使这幅画更有深度，从内部照亮了《蒙娜丽莎》。

Woolly mammoth fur was composed of two coats: an inch-long yellowish brown undercoat that was covered by a coarse dark brown overcoat that could grow more than two feet long.

长毛猛犸象皮毛有两层：一英寸长黄褐色下层皮毛，上面覆盖着一层粗糙深棕色外毛，可以长到两英尺多长。