UNP Female Armor replaces most if not all female armor and clothing in Skyrim by Exeter UNP Main and Skinny body with it's own skin by dimon99 (dimon99 also makes some custom armors) No links provided since some may be inappropriate: You referenced UNP so I will go with that one and list a few armor and skin variants. (think of heads hands and feet as a separate part and they are) There is no body underneath and the game applies skin texture only to the arms which are the only body part there. Leather armor, for example covers the chest abdomen and legs and only the arms are exposed. There may be odd looking skin if lets say an arm pit texture is painted where a thigh should be, or completely black patches where there should be skin. Armors (even skimpy ones) completely replace the body, so the only errors you might see in such a situation is that your character is less endowed, but more importantly the skin texture may not match.

Just to make one thing clear, if you have a body mod with, let say huge boobs, and you then put on armor that is not modeled to accommodate the mass, there will not be anything poking through. This means that with CBBE installed, you must get an armor re-placer to avoid bad skin issues in game and there are plenty of those to choose from. One other key difference is that UNP's texture UV map matches the UV of the vanilla (default) game body and CBBE has a different UV map. Both CBBE and UNP come with there own working body skin and face skin textures. Generally speaking, CBBE ( Calientes female body Big Bottom Edition) is a more curvy body, where UNP ( UNPretend) is more slender, though each has variants that make it more or less curvy.

There are many other great body mods, but these two are getting the most love as far as armor adaptations and skin customization. The two main body mods for Skyrim are CBBE by Caliente and UNP by dimon99 and they are both very well done.

Skyrim unp blessed body