Relationship between the derived velocity and the angular size (IK Tau at the left, R Dor at the right). The solid (open) symbols designate single (one-sided) blends respectively. The error bars for the single lines show the velocity asymmetry, while for the one-sided blended lines the stochastic error is used. The angular size error bars show the difference between the contour-derived and annular measurements. The shade shows the excitation temperature; the symbol size is proportional to integrated flux.