Most skin shininess is caused by excess oil/sebum production. Oily skin usually looks and feels slick to the touch. In addition to shininess, pores might look larger. Make-up is often prone to slipping and sliding. Counter shininess by using skincare products designed to reduce excess oil, without stripping the skin or compromising its barrier function. Look out for Retinol, Glycolic Acid and Salicylic Acid: key ingredients well known for their pore-refining and resurfacing abilities. Mattifying formulas will also help to control unwanted shine.