Another great question! It is not necessary, but throughout my professional career with supermodels, major magazines and all of my experience on the Red Carpet, "prepping" the eye area BEFORE applying the Eye Pencil, definitely helps the Pencil to "grip" onto something more than bare skin. Don't forget, your eyelid produces sebum oil and even if you don't think it does, believe me, it DOES and this can create a smearing effect if you do not "prep" the eye first. Even applying OVER eyeshadow helps. Because this formula is very sophisticated and is bees wax based, it will not absorb oil, so please, "prep" the eye are first so the Pencil can do its utmost best job for you!