Thank you for sharing your digital art, it is nice that you described what you are doing and to find out about this small ethnic group in Brazil. Seeing your process of work, it is easy to understand how you created the portrait and looking at that simple sketch and the final result that are two different world. It is helpful tool to have a sketch so that you keep all necessary details and their proportion. Like the colors you have chosen and that makes an impression of that colored white paste that they usually cover their faces.