I received my iPhone 7+ last October, and purchased an Apple black leather case for it. Loved everything about it. I wear dress shirts for work each day, and keep the phone in the front pocket of the shirt, screen always facing my body; the phone protrudes above the edge of the pocket by roughly an inch. Yesterday my wife washed a load of my dress shirts and found a peculiar stain about an inch above the top of the pocket on each one, in the form of a dark, grainy line in the shape of the top of the phone. This morning I cleaned the case, and wore it in a dress shirt for about five hours, and saw a thin but noticeable line on the shirt corresponding to the position of the top of the phone. I searched the Apple Store and Google, but found no reference to this. Anyone seen/heard this?