Preheat oven to 375 degrees. Cream together the granulated sugar, powdered sugar, butter, oil, and vanilla. Beat in eggs. combine the flour, cream of tartar, baking soda and salt. Gradually add to the sugar butter mixture. Refrigerate for about one hour to make dough easier to handle. Roll into small balls and roll in decorators sugar. Place balls on baking sheet. Find a vase or glass with decorative bottom and flatten each cookie ball down. This should leave an imprint on the cookie. Bake in 375 degree oven for about 10 minutes or until edges begin to brown. Cool on baking sheet briefly then transfer to wire rack.