1& 2-Shake the bottle,  put in a  glass jar a small quantity of  drawing gum and  take  old brushes (you won't be able to use them for another purpose). Paint without coloring and let  dry well.

3-Paint with ink on all the surface, it is  important that no  unpainted spot is left.

4-Once ink has dried, rub with the finger, the drawings appear in white.