The two terms for this discussion are “dress” and “drapery”.

Dress is clothing as worn; the artist has represented it in a believable manner consistent with naturalistic observation. (Don't think that “dress” needs to be a representation of a dress!) While for our previous discussion, muscles were deemed accurate if they demonstrated a visible amount of tension and stress, dress must evidence a proper amount of clothing wrinkles, creases, anchor points or tension lines indicative that the clothing has been worn. The bunching, stretching, hanging, and fluttering may define the texture or actual weight of the garment: wool will have a few large creases while linen will have a multitude of smaller creases. When you take off your jeans at night, they still hold the creases that have been worked into them due to the activities of the day. Anchor points are those parts of the body where movement occurs: the shoulder/armpit, elbow, waist, and knee. As these points move or rotate, the clothing is twisted or tightened. Tension lines result. Even when the clothing is taken off, tension lines remain around the elbow of your shirt, where your shirt was tucked into your jeans, or around the kneecap. In order to judge the accuracy of clothing in art, tension lines need to be present and in the correct locations. If the figure is actively engaged in movement, then such lines and wrinkles need to be deep and varied. If the figure is simply standing still, tension lines may be minimal. (disegno esterno)

Drapery is clothing used for compositional design purposes without regard to the body underneath or its movements. Drapery is obvious when clothes are square and geometric in shape. Creases and tension lines are minimal if existing at all. (disegno interno)