求翻译：1.透底：产生原因是漆膜薄，因此刷涂料时除应注意不漏刷外，还应保持涂料乳胶漆的稠度，不可加水过多。是什么意思？

1. reveal the ins and outs of the matter: the cause is thin film, except when the brush paints should therefore pay attention to not leak outside the brush, paint emulsion paint consistency should be maintained, not adding too much water.