11. In the Gradient Editor pop-up, change the gradient so it goes from a white to light-grey to white a few times (see the image below for example).
12. Click OK to close Gradient Editor.
13. With the "Shading" layer active, use the Gradient Tool and create a gradient from left to right across the selected flag.
(Since the "Shading" layer is above the "Flag" layer. The gradient will overlap and cover the flag.)
14. With the "Shading" layer selected, go to Layer Blending Modes and select "Multiply".
15. Your flag should now have some gradations applied to it like the image below:
