This tutorial will teach you how to digitally paint clouds in PaintTool SAI.
PaintTool SAI is a Japanese program that is useful for linarting and coloring pictures drawn on a tablet. It is similar to Adobe Photoshop, but I find that working in SAI feels like I am dealing with real medium. The colors blend smoother and there's more control. Both programs share similar tools though, so you can easily translate this to Photoshop as well.
Step 1: Step 1: Base
Start with a base blue on whatever sized canvas (I used a 8x12 inch size here). We're going to blend over it so have it be that medium blue that appears on clear days. It's easier to darken or lighten later with blending. Use the brush tool on max size to fully color your canvas in.
Step 2: Step 2: Lightening
Now pick a lighter blue and start thinking about where you're going to want the clouds and lighter areas to go. Start thinking about a light source. If you are facing away from the sun, like in this picture, then the sky will appear lighter to you and darker further away. Select the air brush tool and lightly draw and blend out the lighter areas.
Step 3: Step 3: Where's Your Sun?
After selecting where the sun will be, pick a lighter yellow and place it in the lightest areas. This will most likely be where the sun is hitting your clouds the most. Continue filling in and blending with the airbrush tool.
Step 4: Step 4: Blurring
Now select the blur tool. There's various settings that you can set to any of the tools in SAI. For this one, I used a paper texture, which feathers out the blurring even more and makes it look kind of canvas-looking. Play around with what settings best suits you!
Step 5: Step 5: Blur, Blur, Blur
Once you have all your settings selected, blur out your colors. Add a darker blue farther away from the light source and then blur that out as well. This adds depth and space to the picture.
Step 6: Step 6: Clouds
Select the pencil tool. Start tracing out where you want the clouds to go. You may have to adjust you tablet pen pressure depending on how hard you have to press or how much the sensor picks up your lines. Draw lightly on the tablet to create thinner lines that look further away. The thicker lines will be a guideline to how much cloud density there is in that area as well as future highlights.
Step 7: Step 7: the Paper Acrylic Tool
Select the Paper Acryl Tool. Playing around with the settings with this tool is crucial because it can control the fluffiness of your clouds. In this picture, I have my Acryl tool set to 41 size, 50% min size, and full density. This controls the overall fullness of your tool. In the bottom settings, I have 50% blending, 100% dilution, and 74% persistence. This controls the way the color spreads and blends with previous colors. I also have the brush set to 70% spread with no texture. This is like when you have too much paint on a brush and it leaks out from the brush. I like setting the Acryl tool to Spread because it gives that blurry, fluffy look to the clouds. Playing around with the other settings is up to how you want the Spread to, well, spread.
Step 8: Step 8: Highlights
Once your done blending with the Paper Acryl tool, switch back to airbrush and add in the highlights. Lightly draw in using small, circular strokes. This may mostly be going over old lines as well as filling in places with more cloud density and light. Keep some shadows in however. Think about how real clouds look. They're not completely white in all areas due to thinning out. Select the areas that look the best to you.
Step 9: Step 9: Keep Blending
Switch back to the Acryl tool (don't worry, your settings for this picture should still be save via SAI), and start blending out the highlights. Keep blending with this tool until you've reached the desired amount of fluffiness and color.
Step 10: *Opt.* Step 10: Second Layer
This step is optional, but if you want that sun-kissed glow to your picture, click add layer to create a second layer on top of your first. Select a light yellow and change the opacity. Use the watercolor tool to lightly go over the lighter areas in the picture as well as blending out some of the sky. This gives a warmer feel to the clouds, but if that's not what you're going for, then skip this step and you're all done!