This description usually meant that the character's skin was very fair and pure, almost without any flaws or blood vessels, so it had a transparent texture. If a character's skin showed this kind of clarity, we could think of it as " transparent skin " or " fair skin." Please note that this description may not always be correct because in some cases, the color of the skin may affect its clarity. But generally speaking, the concept of transparent skin was one of the common descriptions in novels.