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

This tutorial was done using a larger version of this PSD file, so feel free to use it for reference purposes: WetTutorial-O.psd

 
Now to start off, I'll be using one of my older pictures, so you can see how this all interacts with an environment. I normally do this while the whole piece is in layers, but for the purposes of the tutorial I'm just working with it as a single compressed layer.

 
Step 1: Flats

 

The first step is to define the shape of the moisture. This is the most important part. For one thing, fluids all behave differently. Water, for example, is fairly thin and fluid sticking low to most surfaces, but it has surface tension, so it tends to "bubble together". Thicker fluids, pudding, for example, will rise higher off a surface. Study life examples and other artwork to see how these things can look, I'm mainly focusing on technique here, learning the style is your responsibility. ;)

 

The first think I'll do is create a new layer, which I call "L", for no particular reason, fill it with solid black, and make it a "screen" layer by selecting that option from the "layer mode" drop down at the top of the layers palate. You'll note that this results in absolutely nothing happening. This is because a screen layer only shows the lightness of the layer, not the darkness, so a black layer is effectively transparent.

My next step is to create a new layer on top of that called "wet", and grouping that layer to L. This means that anything I draw on "wet" will also be screened, just like L. The advantage is that I can work all I want on "wet", creating and merging new layers, and they're all screened, and moreover they only screen the layers below, not each other.

 

For example, in the picture to the right, the dot on the left is a flat color on a normal layer, the two dots in the middle are on two different normal layers, grouped to L as mentioned above, and the two dots on the right are on two different layers that are each set as screen layers.
What using this technique allows you to do is to make many layers while working out what shape the wet areas will take, and they will all be uniformly transparent relative to the body/ground beneath them. This way it's easier to draw the fluids in relation to that background, flowing in and around it.
So to start, we'll drop in a few dots onto the wet layer, just using a small, hard brush to draw in some drops of liquid where liquid is likely to drop or pool in the composition. I use blue because I find it's a solid contrast to skin, but feel free to choose whatever color works for you, it really doesn't matter.
Next what we'll do is try to draw some fluid trails. We do this by drawing a block of color from a drop along a path that drop of water might have taken, and then using a hard edged eraser to erase back out portions of that block to make a watery shape. This might take a lot of trial and error, and on more complex areas might take several layers to achieve. Remember that different fluids have different consistencies and will travel differently. Make not of where gravity would pull a fluid, and if applicable, what other forces might be acting on the fluid (like if it's being sprayed)
Now look at this little bit. I'm going to connect the paths of these two drops, so first I block in color like this (on a separate layer, left top), and then I erase out like so (left bottom).
The connections aren't quite "fluid" enough between them though, so on a third layer, I'm going to paint in little "webbing" between the corners where they touch (right top) , and then erase back the parts I don't want. (right bottom)
 
 
Now these are fairly hard edges liquids, full of surface tension and a bit less realistic than they might be. To add a bit of realism, you might choose to make some smoother edges. For example, taking the blob in the middle, you might choose to use a soft eraser to make it look something like the left picture, or use the smudge (pointing finger) tool to drag out the shape in the right picture, depending on what look you're going for.
 

So, after a little bit of messing around, I ended up with this for flats:

 

And now we move on to Shading and Highlights