Now it's time to finally get to work on that digital painting! Open the PSD file with the flat colors that you did in Photoshop. You'll notice that in the Layers window, all of your named layers are listed just as they were in Photoshop.
Get a brush selected and go to the background layer. We're going to start adjusting the lights and darks in there. Adjust your brush size to be nice and large. You can adjust the brush size using the options menu at the top of the screen, under all of the file menus. You can also fiddle with the opacity and any other features up there. Play around to see what they do. They're different for each brush.
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Remember all those shading layers we made in Photoshop? Here's how we use them. First make sure your colors selected are white and the shading color you chose. A quick way to get the shading color is to use the eyedropper on an area that has only white underneath, like the white of the eye. Or you can just copy a small swatch of it over from Photoshop and use the eyedropper on that. How you do it doesn't matter, so long as the color is exactly the same as whatever you filled those shading layers with.
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Multiply layers work with addition and subtraction of color. White works as your "eraser." Anything that is white on a multiply layer will be transparent. Anything that is any other color, will darken the colors below while adding a slight hue. Black will just be solid black. So using only white and your one shading color, you can actually pull out highlights and paint in shadows entirely on the multiply layer.
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Using the oil pastel tool I've roughed out some fun lights in the background of this image.
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And now using the Artist Oils-Dry Palette Knife, I've pulled out some rays of light with a little texture in them. This is actually totally contrary to the light-logic I have planned out but we'll ignore that for the moment. This is more intended to be background design than actual shading.
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The things you want to consider are where your light source is coming from, how intense it is, and what areas might be cast into shadow. To sort of fix the light logic problem with my image, I went back in with violet and added a defined shadow behind the dog to give an idea of light direction.
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Once you've finished the background, it's time to move on to the shadows on the figure. Now you will finally understand the reason for that complicated layer organization method back in the Flat Colors tutorial.
Go to your Color 1 copy layer. Make sure Preserve Transparency is checked. It should be since we locked the transparency of all these layers in Photoshop. You may want to uncheck the Pick up Underlying Color box if that's checked. What that does is allows the brush to pick up colors on layers underneath the current one. It's sometimes a useful effect, and other times it just makes a mess of things. You decide what's best for each area of color in your own picture. I prefer not to use it for this type of shading work since I want to keep my violets and whites pure on the multiply layer.
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Now pick an area and start pulling out some of your midtones using white. Notice that you don't have to select the color using the magic wand tool or anything. Preserve Transparency will keep everything you do within the solid areas on this layer. Now do you see why it's nifty to have all these different color sections on separate layers? If you had tried to do this all on one layer you would have had to select color areas with the magic wand, some of them would have bled together because Painter does that, and it would have been a big unhappy mess.
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Don't forget that you're painting back midtones. The less white you add back in, the darker the image will be. If you want your character to be mostly in shadow, leave lots of violet. If you want it to have more normal lighting, add lots of white back in.
Keep on going with this layer until you've got the balance of shadows just the way you want.
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And in case you were curious, here is essentially what you've been doing. The shading layer with only white underneath and then nothing underneath would look like this:
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Now go through and do the same thing to the rest of your shading layers.
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You can also add some highlights using a similar method. Make a new layer above any of you color layers, make sure Preserve Transparency is not checked, set the layer mode to "Screen," fill the layer with solid black, and select a color similar to the base color but slightly lighter and warmer. Screen works like Multiply, but opposite: Black is transparent, all other colors tint and lighten, white is solid. You can paint in some subtle highlights this way.
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By now you should hopefully be getting a feel for how the brushes in Painter work. The oil pastel brush involves a lot of blending. I always equated it to painting with butter. Granted I have never actually painted with butter, but I imagine it would be something like this.
You can also, of course, paint directly on your color layers if you want to add additional highlights or shadows, just keep in mind, anything you do to those layers will affect your markings and you could end up accidentally painting over them.
Finally, it's time to save. Go to File>Save. Save your file as a PSD once again. When the little save box pops up, make sure RGB is selected and click OK.
You can go back to the tutorials menu or go straight to the next step.