I've noticed it has something to do with the Stroke Property. See these notes: With Stroke <Path Canvas.Left="0" Fill="WhiteSmoke" Stroke="Transparent" Data="M18.1,4.8C18,4.3 17.6,4 17.1,4H13L13.2,7H10.8L11,4H6.8C6.3,4 5.9,4.4 5.8,4.8L3.1,18.8C3,19.4 3.5,20 4.1,20H...