A while back, someone asked for critique on a piece and was specifically looking for help with grounding/the transition between their horse and the water it was standing in. I put together a little demo to see what advice I could offer, but they'd moved on before I finished so the results never wound up seeing the light of day.

That said, I think that there were some interesting challenges involved—the piece was greyscale, with a backlit/overcast light source and still, shallow water—and I've seen a number of other folks ask about water grounding since then, so I've dug out the files and figured I'd share in case it helps anyone else out.

Different images will need slightly different opacity levels, layer blending modes, and colors. I've included which ones I used, but experiment and figure out what looks best for what you're trying to do! Take this tutorial more as a colleciton of ideas than a set of exact steps to replicate; I was experimenting myself as I went along and your mileage will likely vary.

And when in doubt: reference, reference, reference! Get a glass of water and study the way it distorts things viewed through it. Look at pictures of animals or people in different bodies of water, and pay attention to what you can or can't see beneath the surface. The more you look, the more you'll understand how water works, and the more easily and realistically you'll be able to replicate it in your own art.

So, that said! Let's jump in:

Step 0: Basic Setup

I'm using Clip Studio Paint for this demo, but I'm not using any particularly fancy features so Krita, IbisPaint, Procreate, and so forth should all work just fine. The only features this requires your software to have are layers, layer blending modes (multiply, overlay, screen, etc.), and a few standard brushes. If you have clipping masks and layer masks those'll make your life a little easier, but you can get by just fine without them.

Let me preface by saying that I did almost nothing in the way of body prep for this, since it's just a demo rather than a final piece. I'm going to go ahead and assume you've already done your prep, and we'll just focus on the grounding of the horse into the water.

(Also, a note to the mods—the image credits were easy to read on my calibrated screen, but when I switched to my laptop's pretty trash monitor they're a fair bit less so. I'm not sure how well they read on a normal screen now, so please let me know if they aren't clear and you'd like me to reexport/reupload. By the time I realized I was already 22 images deep; my apologies.)

For context, here's the raw horse and background stock:

To prep it for the demo I added a very subtle pin light layer to make the lighting a little less harsh, and cleaned up the bottom of the hooves:

(I also realized after exporting that I turned on a shading layer down on the bottom of the water by mistake, but just... ignore that, lol; we'll get there in a sec.)

Step 1: Water Surface/Falloff

I start off by adding a gentle blur to the edges of the hooves where they'll be underwater (depending on your image, this might include a little soft-brush erasing to get a nice edge; play around a little and see what works for you). This eliminates the awkward sharp edges from the horse layer where they'll ultimately be blended into the water and gives us a good starting point:

Then, to add the surface of the water, we copy a section of the background to a new layer above your horse, and then cut out the area where the surface of the water meets your horse's body.

In most cases, natural bodies of water like rivers and ponds have at least a little sediment in them, which fogs your view the deeper something is. To mimic this, with a soft brush, erase gently along the water line to add some transparency. You want the most transparency near the surface of the water and a gentle gradient down from there, but be sure not to erase too much; you don't want to lose the hard edge of the water.

I've highlighted the section I've copied in green to make it easier to show what I'm doing here:

Without the green that looks like this:

Step 2: Ambient Occlusion (pt.1)

The closer two surfaces are to each other, ambient light is blocked and shadows are darkened. The effects are most visible where surfaces meet, which means that where your horse intersects the water there will be a thin, subtle shadow on your horse's body.

With a soft-ish brush, on a new layer between your horse and the water, trace the edges of your water in black (you want to paint thick enough lines to reach a little above and below the water's surface).

If you have clipping layers, clip this layer on top of your horse so that it only affects the horse and not the water. If not, use whatever method you find easiest (erasing, painting within a selection, etc) to make sure the edges of the shadow don't hang over the edge of the horse.

If I hide the water layer, that looks like this:

Set that shadow layer to Multiply, then drop the opacity until the shadow feels believable. In my case, I liked 40%:

Step 3: Reflection

This water is a bit murky, and the light is coming largely from behind our horse, so we'll be seeing more of a soft shadowed reflection than a crisp, mirrored image.

Duplicate your horse layer and flip it vertically to get a quick reflection (it won't be perfectly accurate to how a real-life reflection would look, but in our case that's fine). Then add a gaussian blur to the reflection layer and/or use your blur tool until the haziness feels like it matches the water in your environment.

Set that layer to Overlay, which should turn it into more of a shadow than a lit reflection.

In my case, I found a soft-edged eraser near the hooves also helped things feel more believable—it both mimics a bit of bounce light near the horse's feet, and also hides the fact that the hoof reflections don't line up right when you use a copy/flip method. Depending on your horse's pose you might also find that using the liquefy tool or some of your fancier transform tools (like mesh transformations or puppet warp) useful to better align the reflection.

Step 4: Ambient Occlusion (pt.2)

But wait! The horse's proximity to the water will also block a little ambient light. This will be a lot more subtle than where the water meets the hooves, but help make things feel more realistic.

Add a soft shadow underneath the horse to another layer, move that layer below the horse and above the rest of your water, then set the layer to something like Overlay or Hard Light and adjust the opacity to something juuuust subtly visible. Don;'t worry about light direction for this one—we only care about the proximity of the horse to the surface near it.

At high opacity, this is roughly what it should look like:

And then dropped to the final, lower opacity:

Step 5: Refraction

We've got our basic shadows in now, but water distorts our view of what's beneath it and things will feel more realistic if we emulate that in our piece! To do that, I find a hard/higher-density airbrush helpful, using roughly the color of the part of the horse that's underwater. We don't need to be super precise here, but add another layer and draw some scribbly little lines roughly over the body where it's underwater, with a bit of offset horizontally and vertically. Again, this is partially feel; try different things until you like the look of it, and don't be afraid to look up reference images to see how refraction looks in real life.

At full opacity:

I used blending mode Hard Light at about 35% opacity for this layer; if you want your water to look clearer or less still, you can definitely use a higher opacity.

(Calm water is, in my opinion, a lot harder to make look believable than moving water because you really have to lean into the subtleties and can't lean on ripples as heavily to blend things into the environment. A lot of these layers might seem almost silly an unnecessary on their own, but in combination is where they shine.)

Step 6: Surface Tension/Adhesion

The properties of water mean that wherever the water's surface meets your horse, it's going to rise juuust slightly where it clings to their body. This means there will be a little bit of a highlight just around the hooves in my case.

You know what this means... make another layer! This one can just go straight on top of your water layers. With a thin, hard-ish airbrush, paint around the water's edge. Then set the layer's blend mode to Screen and again, drop the opacity until it feels nice. I used 37% opacity for this one.

I kept this a little loose, making sure the edge of the water was lightened but adding a little extra movement and a very subtle bit of ripple by a couple feet.

(In related news, if you've ever wondered where an art degree will lead you, the answer is apparently "standing in the kitchen sticking your finger into a glass of water to make sure you remember how water works.")

At final opacity:

Step 7: Ripples

"But 'Fell, I thought this was still water and you said we can't lean on ripples?"

Well, the water is calm, but living animals are pretty much always moving at least a tiny bit, even when they're standing still. That's why video games generally have idle animations for their characters; animation that fully stops when a character stands still feels unnatural and kills the illusion of life. Even when we're standing in one place we're still breathing, our hearts are beating, and we're making tiny micro-adjustments in our balance. And as a result, an animal in the water is going to cause at least a tiny bit of movement in the water... but in our case, tiny indeed.

So! Let's add a few layers of ripples to help add that sense of life and movement; we're just going to keep them very subtle. Reference is your friend here, especially in seeing how ripples interact with each other when there are multiple sources.

I used a small, denser airbrush for my highlights, and set this layer to Soft Light at 10% opacity:

For my shadows I used a slightly softer airbrush on my first pass, blurred it a bit, and then added a second pass in some areas to help get some diversity in how defined the ripples were. These I set to Multiply at 6% opacity:

I still felt like something was missing so I added another layer of highlights, these drawn with a harder airbrush and then partially blurred. I set them to Screen, at 100% since the blur had already lowered the opacity a bit:

And then with those three all combined at their final settings, we get:

Step 8: Final Details

We're nearly there! Things are looking pretty good, but there are still a few more finishing touches I found helped out.

The first is adding a tiny bit of texture around the hooves. You want to keep this especially subtle if you're working with still water, since your horse isn't splashing around kicking up droplets and froth, but especially since I'm working with a slightly grainy background adding a little texture around the hooves helps blend things together and make it less digitally-perfect.

For this I tried out a few different brushes with some more texture to them, found one that felt good, and added a little extra highlight around the hooves (I think I used Clip Studio Paint's dry gouache brush for this, but I'm not 100% certain since it's been a few months since I initially did this; a fair number of grainy brushes should work fine for this depending on what you've got available in your software of choice).

Setting the layer to Screen at 70% felt nice, I thought.

And then for the last few touches, I added one final layer on top, on a middle-ish opacity, and did some eyedropper/airbrush painting until I was happy. This one looks a little goofy when I bump the opacity up, but most of what's happening here is that I've lightened the hooves slightly where the water would bounce a little bit of light up onto them, and added a little more defined shadow to the ripples/refractions just beneath the hooves. It's a little scribbly because it's at low enough opacity not to need a ton of precision; this layer is just me being nitpicky, haha.

At an opacity way higher than I actually painted it on:

And then...

The Final Image:

Put that next to the starting image and you can see how all the subtle layers work together in comparison:

There's definitely further you can go with something like this if you have the time an inclination; I was hurrying a fair bit to get this together in a single evening and just using it as a demo. With some actual reference and time you could really refine it into a believable image.

Some other things to consider:

• If you're working in color instead of greyscale, this should all more or less apply but you might want to add a little color into your highlights and shadows that match the lighting of your scene instead of just using black and white.
• If you've got a lot of bright light reflecting off your water, you'll likely wind up seeing some of that light bounce up onto your horse, under the fetlocks and such.

Have fun putting your horses in water! Feel free to ask questions if anything is unclear. And don't forget to use reference for things like this, because it really does make a world of difference.