If your character is wearing either a robe or plate armor together with a cape or mantle, the latter will clip against the former.
SAVED GAME: link
Load the attached saved game.
Zoom in on the party.
Observe that the protagonist's cape clips against the plate armor; further observe that Aloth's and Durance's capes clip against their robes.
Go to the inventory screen and rotate the character models to see the issue up close.