The surface is already making decisions before you touch it.
Wet ground painting — working into a layer that hasn't dried — is one of those techniques that sounds like a shortcut until you try it. Then you realize it's more like a negotiation. The paint you lay down doesn't go where you put it. It goes where the wet ground allows it to go, and those are different places.
I started working this way about three years ago, after a conversation with another painter who described it as "letting the painting have opinions." I thought that was precious at the time. Now I think it's accurate.
The ground — usually a thin layer of oil medium or a previous wet passage — has its own viscosity, its own temperature, its own relationship to the pigment you're introducing. Cadmium yellow into a wet umber ground doesn't behave the way cadmium yellow behaves on dry canvas. It softens at the edges. It picks up the undertone. It becomes something you didn't plan.
This is either a problem or a gift, depending on what you're trying to do. If you're trying to execute a precise vision, wet ground is your enemy. If you're trying to find something you didn't know you were looking for, it's the best tool in the studio.
I've been writing about this kind of process-led work over at fine art practice — the way fine art practice changes when you stop trying to control the outcome. There's a related conversation happening at creative community about creative community and how makers support each other through uncertainty. Both feel relevant here.
The practical reality of wet ground painting is that you need to work faster than you think. The window closes. The ground starts to set, and what was fluid becomes fixed, and the decisions you didn't make get made for you. This is not a metaphor. It's just what happens.
But in that window — sometimes twenty minutes, sometimes an hour, depending on the medium — there's a quality of mark-making that's impossible to replicate on dry surface. The edges breathe. Colors merge without muddying. The painting looks like it was made by someone who knew exactly what they were doing, even when you didn't.
The surface decides. Your job is to be ready when it does.
There's a piece at handcraft and process about handcraft and process that touches on this — the way the material leads and the maker follows. Worth reading if you're thinking about this kind of work.