Are these ink drawings?
No. These are Linocuts. Linocut is a form of Relief Printmaking.
The image is drawn onto a block of linoleum and hand-carved with wood carving tools. Ink is rolled onto the linoleum block, paper is placed on top of the block, and the block and paper are run through a printing press.
How long does it take to carve a block?
I have no idea. I just carve them until they are done. My print "War-Pig!!" took 16 hours just to carve, so there's a baseline.