Toolbar Box Nine: RGB, Opacity & Size

Sliders IconsRGB, Opacity & Size: RGB, Opacity (Alpha) and Pixel Size Slider Adjustment Bars

RGB: Stands for Red, Green and Blue. Custom colors may be mixed using the sliders for red, green and blue. There is a bar underneath the RGB sliders that always shows what the current color is. Some general things to know about using RGB: Black is the lowest setting on all three bars, or 0-0-0. White is the highest setting on all three bars, or 255-255-255. Except for the highest or lowest settings, whenever all three bars are at the same number the color will be a tone of neutral gray. A setting of R=255 with G and B at 0, for example, would be pure red. I never use the RGB sliders to pick colors because it is so much easier to use the HSB Color Picker/Mask Window. (Read more about color at the Wikipedia website mentioned on the page for Color Palette.)

Opacity (Alpha): The opacity tool allows you to set any brush, filter (rectangles, ovals, textures) or color fill to a setting between 1 and 255, 1 being transparent and 255 being totally opaque, with a graduated range in-between. Use the slider to adjust the setting you want before you begin drawing or creating shapes, lines, textures, fills, etc. Wherever you want something to partially show through something else you will use this tool. It's another tool you have to experiment with to get a feeling for how it works.

This tool is essential for doing graduated blending of colors in Shi Painter since there is no Blend/Smudge Tool. For a very smooth, photorealism type of blending I use the airbrush at settings between 10 and 80. For a more painted look I will use the watercolor brush set to somewhere between 20 and 90 for blending. When you make a light stroke over a dark color (or vice versa) the low opacity setting causes a third, intermediate color to appear where two tones of a color overlap. To blend, I pick up that intermediate color and overlap it with the first one. I continue to do that until I have the gradation of tone/shade I want.

The example below illustrates a blended gradient created using the airbrush tool and the technique described above. Watch the animation for airbrush here and the one for watercolor here.

Gradient Blending

Size: The size slider changes the size of your brush stroke, dodge, burn & soft tools, erasers, straight line, rectangle outline or oval outline. The number represents individual pixels. The 0 setting is half a pixel and does not make a solid line. Sometimes when you change tools the program automatically changes the size slider so check to make sure you have the size you want before you start. The maximum size varies for different tools. It's easy to check by pulling the slider all the way to the bottom of the box. The small black number you see will be the maximum. If you have trouble fine tuning the number setting, use the up and down arrows on the right side of the box instead of dragging the slider bar.