The red and green curves in Figure are obtained from the measurement during growths 2 and 3 presented in Figures . The inclusion of points from either covered or bare parts of the copper surface results in partial splitting of the XRR curves. To illustrate that the measured points belong to two different states of the sample's surface, XRR curves measured with the same approach for bare liquid copper (grey) and the copper entirely covered with graphene (blue) are also shown in Figure . As we can see, the described method allows obtaining two XRR curves corresponding to two coexisting states of the system.