Well, a dark, rich black is the still elusive goal.
I'm working with transparent, water-based pigments and printing by hand with a baren on handmade, textured paper so it's harder than you'd imagine.
I finished carving the six blocks for the domino print and started try to figure out in what order to print the blocks and how.
Here is a reference trial.
One of my blocks printed with fairly dense, straight out of the bottle SUMI black ink.
It's a warm, inky black and covers very well if you paint it with a brush. But brushed onto the block and printed once it looks like this:
If I brush another layer of sumi and print it again it will get quite a bit darker but the gray tone is the white of the paper showing through--some of it is the texture of the paper and some the grain of the wood. Pressing harder will help.
I could use this as a griseille--a grey value underprinting and then attempt to print colored glazes over the top to achieve the colors I'm after.
The other way to get black is to overprint different colors. The process colors cyan, magenta, yellow and black should give you a dense rich black.
I've roughly tried that here with a yellow background layer, then a warm red, then a cobalt blue (not really cyan but transparent) and then Carbon black in 1) and Phthalo blue in 2. They are still "gray"--there's still too much white paper showing for my taste, but the mood/texture of the dark is to my eye more interesting if still
Tomorrow I'll switch the order, play with a real cyan/magenta combo and see what happens if I drop the yellow background. Today's printing has shown me that there is still some general trimming and cleaning of the blocks to tighten up the registration and get rid of some stray marks before printing the edition.