35 ILCS 505/1.5

"Blending" means the mixing together by any process whatsoever, of any one or more products with other products, and regardless of the original character of the products so blended, provided the resultant product so obtained is suitable or practicable for use as a motor fuel, except such blending as may occur in the process known as refining by the original refiner of crude petroleum, and except, also, the blending of products known as lubricating oil in the production of lubricating oils and greases and except, also, the dyeing of special fuel as required by Section 4d of this Law.