Complex sentence: In the case of a blister, the moleskin is cut with a hole in the center so the fabric does not adhere to the blister directly; the thickness of the surrounding moleskin protects the blister from further friction.
Split into simpler sentences: In the case of a blister, the moleskin is cut with a hole in the center so the fabric does not adhere to the blister directly. The thickness of the surrounding moleskin protects the blister from further friction.