They believe this characterizes a technique of painting that USES a glaze, or very thin layer, to build up shadows in the face.

他们认为这是使用釉料或者很薄的涂层来绘制脸部明暗这个艺术技巧的特征。

youdao

Apply a thin layer of the mixture to your face, and let it sit for 10-15 minutes.

在脸上涂上薄薄一层，等10 - 15分钟。

youdao

She had applied a thick layer of sunblock on her face to keep the sun from burning her snow-like skin, but she seemed to be toasting.

她白雪似的肌肤上敷了一层厚厚的防晒霜，可是她看起来像是做过日光浴。

youdao

We had two six-wheeler trucks, too, but it was warmer in the buggy: you have an extra layer of clothing and a full-face helmet.

BBC: Polar express