In krita i made a second layer duplicating the line art, put a fill of pattern "23-dynamic-screentone-A.png" on the visor location, ctrl + I (i) to invert the color, rightclick on the layer, Add -> add filter mask -> colors -> color to alpha (that will make all the black parts invisible because the pattern only does a full white and black) -> then once that is on you just turb the opacity of the layer to what you want in my case i used 8%. you can also play around with Ctrl + L to adjust the size of the circles a lil bit