Blending ... whaat? In digital-painting, you can paint with 'blending modes' applied on your brush. In short ; a blending mode is a math formula telling your software how to mix two colors : the ones on your canvas and the one on your brush. Knowing a set of useful blending modes can assist and ease your work for painting specific rendering.
Goal : This video tutorial ( on top ) aims to offer to the digital-painter pratical tips to use blending-modes on his brushes. I'll not show all the blending-mode as other tutorials do. I'll not perform here a cold listing of all blending modes as I saw on other tutorials. I'll also not show formulas and math : it's a painting tutorial. I'll aslo keep the list minimal with five one.
Where I can find it ? In Krita 2.9, the blending modes applied to your active brush is displayed on a button in the top toolbar. The default one is named 'Normal' , press this button and you'll get a list. This list contains favorites on top, and subcategories to unfold under. Each blending modes in the subcategories can join the top favorite list by checking the checkbox next to them.
Short summary :
Light, glows, coronas, lazers, neons ; this is the blending mode I use to manage all my light effect. It has advantage of a stronger saturation and contrast over other brightening blending mode (Linear Dodge, Addition, Screen).
In Krita : Lighten > Color dodge
Contrast, vivid, boost colors here is my primary usage of my favorite blending mode : Overlay. Overlay is a conditionnal blending mode : it combine two blending mode in one. If you select a grey 50% ; it will do nothing. But over , and under this grey , Overlay will switch to a brightening or a darkening blending mode. Painting wih dark tones will intensify and vivid the area. It can be used also to boost colors and give an object the first role in your composition. Overlay is also known for it's conveniency on layer to 'overlay' a texture, or a pattern over a surface. 'Soft Light' is a more subtle variation of 'Overlay'.
In Krita : Mix > Overlay
Note: fun bug in Gimp since 10 years, 'overlay' is similar to 'Soft light'.
[edit 12/2015 : It was finally fixed this month in Gimp 2.9! yay! ]
Lighten is a comparative blending mode. Lighten will paint only if the value on the canvas is darker than the value on your brush. This propriety help me to shift values in the distance, and split different grounds on my artwork.
In Krita : Lighten > Lighten
Changing the color is the obvious mission of the blendings modes 'colors'. I use the color blending mode to do a first pass of colorization over my grisaille. The result is often dull, and greish, but that's easy to fix with another pass of the overlay blending mode. I also use Color (HSY) with grey to desaturate zone, or do hue corrections.
In Krita : HSY > Color and HSL > Color HSL
Shadows, stains, dirt, glazing, it's one of the king of the blending mode in digital-painting, the darkening-only one ; Multiply. White is equal to full transparency with multiply.
You can draw with this one on the surface of a shaded object, glaze skin shading to inject a bit of blood under the skin, add dirt or paint big casted shadows.