In answer to a question in the comments on the last-but-one painting of a Blue Heeler, I begin by marking out a few lines with whatever is to hand - often, a pastel pencil. In the case of dog portraits, I only need to make sure the eyes and nose are correctly positioned. The more complicated the painting, the more lines I need.
Then, in the case of these dark paintings, I brush in the background in black acrylic paint, because it dries quickly. It is difficult to get the values right if I don't put in the darkest darks. Looks like this:
Occasionally, I might come back in and put an extra layer of fur when the first pass has dried, but not in this case because he is a smooth-coated dog and it wasn't necessary. I re-work the background in oils at the same time as painting the parts of the dog that are adjacent.
Whiskers and signature will follow next day or whenever the paint has dried. This is so I can wipe the whiskers off if needs be without ruining the work - blobby whiskers are obviously not a good look.
In response to the specific question about whether I use Raw Umber to do the underpainting, the answer is not on small, daily paintings like this one. For larger paintings with more difficult compositions, then yes. Any piece where I might get in a muddle with the values, basically.
Thank you for looking at my paintings and have a lovely weekend.