This is the default Media selected at startup. It's perfect for subtly spraying on paint and image processing Paint Modes. Its smooth edges give a professional appearance to your images.
If it seems slow to use, try turning up the pressure or decreasing its size.
Smear forcibly pushes pixels around the image. Try loading in a picture of a face, and smearing the eyes, nose and mouth in an almost goo fashion.
Smudge is one of the most useful and diverse Media. It's perfect for blending and blurring things together, and creating attractive effects. Try painting something with the other media, then smudging it.
Chalk does a very good impression of chalk or pastels. Use them like the real thing, scribble, scribble, scribble, using lots of different shades of colours on top of each other. Use Smudge to blend them together just like using your fingers.
Watercolour can be used for other things than just creating gorgeous paintings that look like they were hand drawn. Try using Watercolour to RubThru to a different image, or using it with the Fire paint mode.
The following Media all work best using the Fire Paint mode. The more you paint, the more intensely white and fiery the effect becomes.
Sparkle is like drawing with lots of little lensflares. The sparkles have some amount of randomness when drawing.
Neon works very nicely with vivid or pastel colours. If you find that the effect builds up into a white splodge whilst trying to draw lettering, press Fix after each stroke.
Photogenics allows you to paint on lensflares faster than you can click "Render" in your 3D package. Use the size and pressure sliders as usual to change the size and power of the flare.
Start from the bottom of the image, and slowly with the left mouse button held down to create a wall of fire type effect.
A nice fire effect.
See the FireEye tutorial for ideas on how to put this to great effect.