"Glory be to God for dappled things" - Gerard Manley Hopkins
My husband found that Victorian-era quote a few years ago. I'm not sure Mr. Hopkins was thinking about horses when he wrote that line, but I certainly share his sentiment. Dappled horses - greys in particular - are among my favorites to paint. I started working on a group of them last week and will finally get to return to work on them today.
I paint my greys in stages, so they usually go through a half-dozen or so firings. This guy is really early in the process, having been through one firing (his mane, tail and legs) and just getting the coloring for what will be his second. You can just barely see the first layer of light grey on his forehand, which I have begun to erase. As I've mentioned before, when working with underglaze dappling is done by removal. You can see my main tools for this there in foreground - a stiff white EraserStik (sadly no longer made, so I'm always searching for them) and a softer pink Faber-Castell eraser pencil. The large, soft brush helps soften the edges of the dapples so the underglaze doesn't "pile" up and create a dark rim around the erased spot.
This first bit of dappling is always the hardest because the grey underglaze is much, much paler when it is raw than when it is fired. That makes it hard to see what you are doing. Usually I try to spray one light coat on the neck, forehand, and barrel, dapple those areas and fire again. Then when it comes out of the fire, that first coat can serve as the underpainting.
This guy is at that stage now. I can better see my dappled pattern, and I've added the first layer to his hindquarters. On an intensely dappled horse with a primarily dark hindquarter, I often leave that area until later so I don't risk marring it while handling the horse. Here I've also wrapped the finished areas, and the unworked areas, so they don't get hit with any overspray. Because the grey is so pale, it's easy to overspray without knowing it until after it fires and becomes obvious. I haven't wrapped those areas completely up to the new, though, because I don't want a line where the border was. (That's also why the wrap around his head is so loose - no hard edges in case I do spray in that area.)
This guy is one step further than the Andalusian above, with one more firing on his hindquarters. Unlike the others, though, his legs were left unfinished up until this point. His legs will remain relatively light, so they have not yet been sprayed at all. If the color calls for a dark leg, I usually paint those first so I have a good hand-hold. Most of the dark tones I use are pretty sturdy after they are fired, and even when they get rubbed they can be resprayed without any real harm. If I marred a light leg my only option would be to go darker. So his legs will stay light until closer to the end. Today, I'll start adding the red tones to his hindquarters, since he's to be a rose grey.
You'll notice that none of the faces on these guys are shaded at all. On greys I like to do that at the end so I can get a better feel for the finished look. That way I can adjust how light or how dark the face shading needs to be to balance out the piece.
And here you can see how my preference for dark leg hand-holds creates legions of only-the-legs-painted bodies on my workbench! All three of the horses on the left became, or will become greys (this is an older picture). The Arab at the top right is to be a dappled bay (hence the golden tones above her black legs) and the claybody below him will a loud bay leopard.
That's also why tobianos are the "easy" color in underglazed ceramics. Their white legs mean that they start out with safe handles. No rubs to worry about! They get finished in far fewer firings, too. But I still find the dappled horses hard to resist.