Wrinkles can develop overnight, from sleeping late at night to sleeping on your side and stomach. These positions cause mechanical pressure on the face creating sleep wrinkles. Moreover, cotton and flannel pillowcases may be at fault since they are harsh and pull and drag on the skin.Wrinkles can develop overnight, from sleeping late at night to sleeping on your side and stomach. These positions cause mechanical pressure on the face creating sleep wrinkles. Moreover, cotton and flannel pillowcases may be at fault since they are harsh and pull and drag on the skin.