This is not something I do to all of my mische technique paintings, but I do find that it is very effective when it’s needed. During either the red or yellow glaze stage of the underpainting, you can add either a dark umber or like in this case, indigo, to your painting to deepen the shadows where you want them. This draws out the value range even wider and often saves time once you are in the color stage. Glazing shadows dark enough can be challenging and this way you preserve the translucence of the glaze while simultaneously achieving a velvety shadow.
I hope you enjoy this video!
I’ll be following up this one with how this all looks once you apply the blue glaze.