Japanese women, even high school girl use oil blotting paper for keeping make up or own skin clean and beautiful.
Oil blotting paper absorbs your oil on your face. Since the oily face cause makeup-comes-off and makes your skin not clean, it is good to wipe your oil constantly with the blotting paper.
How to use the paper is just to press the paper on your face for seconds, especially around your nose, forehead and cheek then you can see the paper absorbing oil and gets discolored. Sometimes you need several papers to wipe the oil off.