Oni's "Wetness" Tutorial

Welcome to this tutorial on how I color. I am using Photoshop 5.5 on Windows. The Mac key commands are different, so look in the help files to see what they are. I also use Photoshop CS sometimes, but I don't much like it. The brush pallet doesn't adequately suit my needs.

The purpose of this tutorial is to teach the techniques I use to do "wetness", fluids of various forms. A more basic tutorial, which expands on some of the techniques used in this one, can be found here: Tutorial 1: Basics

 
Step 2: Shading

 

So now we have the shape, what do we do about shading? First, we merge all the "wet" work layers, and separate them from the "L" layer. Then use ctrl-u to lighten the layer from blue to white, reduce it's opacity to about 45% or so, enough that you can see both the wet flats, and whatever is below it.

Next, make a new layer, I call it "w", and group it to the Wet layer. This is the layer we'll be painting shading on.

I tend to use a soft brush for this, but for a more anime look you can use harder edged brushes. Just draw in where the light would be shadowed on any solid object. You can use any color that you feel contrasts well with both the background and the white, it doesn't really matter at this phase.

After a little bit, I ended up with this:

What you next want to do is ungroup the layers, which makes the w layer spill out all over the place, but then, with the "w" layer selected, drag the "wet" layer onto the "create layer mask" button. This will create a layer mask on the "w" layer that is the shape of the "wet" layer. Apply this layer. You'll see why we needed to separate the two in a minute.

Step 3: Highlights
 
Next you want to add the highlights. This is actually the most important part for doing wetness. Proper highlights are almost all you need to define a wet area, as you'll see when you have the highlight layer and can hide the others.Water has very sharper highlights, so you want to at least start by using sharp edged brushes. I like to keep the wetness highlights separate from the other ones, so I make a layer I call "wetlights".
Onto this layer, I might paint in a blob of white along the upper, light facing edge of the water,and then erase out like so:

I might then use the smudge tool, with a small, hard edged brush (anything larger than the blob you're pulling out), set to around 20% strength, and drag that blob out.

This is kinda tricky and will likely take a lot of practice to get right. You want to start near the edge of the blob you're moving, and draw out in several strokes. The farther out each stroke starts, the less material is dragged, so the smoother and more transparent the result. The closer to the solid white you start, the more material is moved, and the thicker and more transparent the stroke will be.

 

For example, here is a 25px hard brushed white dot, drawn out with a single stroke of a 45px hard brush at 20% strength, drawn from the center of the dot outwards.

Three more similar strokes gives me this:

 

Play with the smudge tool a lot, there are some great effects you can get out of it, although it is a very imprecise tool so it can take practice to get a specific effect.

After about 8 strokes, this is the result I came up with. The second pic is with that layer inverted, just so you can better see what's on it.

 
You could instead use the soft eraser at a large size to soften an edge.
 

One other technique I use on a soft wet, wrinkled surface like a lip or something, is to use a small, low opacity brush. I don't have one of those situations in this pic, but I'll just throw one out there as an example:

To generate this effect, take a tiny brush, one of the two smallest ones, and set it to around 20% opacity. Then just stipple in the line, layering the dots to make larger, brighter highlights, and training them off to show the gaps in the highlight do to the unevenness of the surface. You might then want to go back in with an eraser of the same size and opacity, and erase out bits that end up overly thick, back and forth until it looks right to you.

Remember that you can use the number keys to set opacity, 10% for each digit. (ie for 20% you hit "2" )

 
So, after applying those technique, I ended up with a wetlights layer that looked like this over the highlights (left), and this on its own, with the wet layers transparent.(right).
 
 
Step 4: Cast Shadows and Finish
 

Ok, the next step is that you want to hide all the wet and wetlight layers (as if you'd never done any of them), select all, "copy merged" (ctrl-shift-c), and paste. this will create a layer of everything but the wet stuff combined. Name this layer, for the moment, as "mask" or something. You'll also want to duplicate the wet layer for this (by dragging it onto the "new layer" icon), and put the duplicate on the layer beneath it. Rename it to "wet shadow" if you want, or just leave it as "wet copy".

Now, make all the layers visible again, and set the opacity on all of them to 100%. Duplicate the mask layer 3 times so that you can group a copy of it to each of the "wet", "w", and "wet shadow" layers. The only wetness layer that you should actually be able to see at this point is the wet lights one.

 

Here's some magic time though. take the "wet copy" layer and set it as a"multiply" layer. Then use "nudging" (the arrow keys while the "move" tool (v) is selected) to nudge that layer a few pixels down, and perhaps to the side of where it was. Magically, a basic cast shadow is made!

Note that you will have to go in and erase the shadow in places, such as at the top of some of the drop flows (where the shadow won't connect to the flow right), and at any point where a drop falls through space (like that one on her lower side dripping into the puddle).

If the resulting shadows are a bit too harsh for your needs, you can now make the layer "normal" again, which makes them vanish, and then either lighten or darken the "mask" layer grouped to it, or overlay another colored layer on top of it to make shadows of different colors, saturations, or darknesses. Play with this a bit.

 
 

Now to generate a "clear water" effect, we're going to leave the "wet" layer alone for now. We could choose to lighten or darken the mask layer grouped to it if we wanted a different effect, but we want to leave it as a normal layer itself, or you'd see the shadows below it.

What can be fun though, is to take the "w" layer, and lighten the mask grouped to it. This results in a "reflected glow" effect coming up from the underside of the water. This sometimes looks right, sometimes doesn't, use your own judgment.

 
 

If, on the other hand, you're making more of a "thick fluid", then you'll want to play things differently. First, hide the "w" layer. Then HSV the mask grouped to the "wet" layer until it's mostly white (or whatever color you want) You typically don't want this layer completely white, because you want to retain the illusion of transparency.

Next you want to take the mask layer grouped to "w", and put a layer above that, filled with a single color (blue maybe), and play with it's opacity until the result gives a nice shadowy contrast to the base white.

 

One other thing you might have to do is to remember the overall shadows of the piece. In this case, the shadows beneath her are dark, while the white fluid is not, so to correct that, we paste the mask layer again above the mask layer grouped to "wet", and then use a large, soft eraser to erase out a portion, leaving only the area towards the bottom of her side and on the ground. You can then lighten this layer a little bit, but not as much as the other mask layer was, making the white lighter than the ground, but not as white as on the top, in the light.

I would normally merge this layer, and the other masked layers into the layers beneath them when I was done with this stuff, but I'll leave them in the example psd I'm including, so you can see them.

And there we have it, the finished piece:

 

Play with these techniques, have fun, make good art. ;)

If you have any questions or comments, you can email me at ohoni@hotmail.com

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