The brush types are on the top of the Brush settings panel.

Click the brush image icon on the top left of the tool panel to bring up the Brush settings panel.

  The Anti-aliased pen (AA Pen)
  Internal brush
  Custom brush

The AA Pen is always a round shape, however it can produce very smooth looking lines.

Many of the pen presets use the AA pen.

It is possible that the sampling of some input devices such as tablets can be lower than desired.  This situation can be aggravated by other conditions, such as the system configuration and speed, and the size of the buffer.  This can result in unpleasant line segmentation.

Spine based input on the prefs panel will help with it considerably.

One interesting (lets call it a) quirk of the AA pen, when used with the line tool, is that you can alter the size from one end to the other.  Do this by altering the brush size each time before you draw.

Among other things, this can be useful for creating laser beam effects.

Internal brushes are the little images you get when you use the Brush images panel. Most, but not all of the media presets make use of them.

Internal brushes are limited in size to 35 by 35 pixels, but they are conveniently built into the program so you can access them at any time.

Right click the brush image icon on the top left of the tool panel to bring up the Brush images panel.

Changing your brush image can drastically alter the effect of your brush.  By applying additional settings that will be covered in the section on Brush Settings, you can begin to simulate traditional medias, or even unique effects.

Internal brushes can be anti-aliased.  This means that they are smoother looking when scaled.  Sometimes this is desirable, and sometimes it is not.  If you were working with pixel art, you might not want anti-aliasing.  Anti-aliasing can be turned on and off on the Brush settings panel.

Note that while the scaling of internal brushes can be anti-aliased, the placement of internal brushes is not anti-aliased.  The placement will always fall on pixel coordinates.  This might  make the internal brush look rough, or pixilated compared to the AA pen.  Again, sometimes this is desirable, and sometimes it isn't.  That's why you have a choice.

Should you want it, you can get a single pixel brush by pressing the comma key.

You can load in new sets of images, called Brush sets.  Click the 'Load set' button on the bottom of the Brush images panel.

You can select the folder containing your brush sets.  Several sets are available.  You may have them already, or you can find them online.

Brush sets are folders that contain BMP images at 35 by 35 pixels.  They are typically 8 bit images, to save space. There are usually about 40 of them in a directory.

This can be a bit of work, but it's mostly the work of creating all those brushes.

You could also work from an existing brush set and replace images with bmp files as you see fit. Internal brushes are always no larger than 35x35. Luckily custom brushes work just like internal brushes but don't have the limitation.

  Almost all of PD is based around the idea of making your own brushes. You do this with the brush selector tool on the tool panel.

You can clip out a rectangular area around your image, then drop out the colors you don't want in it (make them transparent)

Making part of a brush transparent is called a 'brush key'.

Say you picked up this cloud image to make a brush out of it.  You can clip a rectangle area around the cloud, then drop out the blue of the sky with a preferred tolerance of how much blue to drop out.

The Low clip and High pass controls let you adjust how much of the color to key out.

Low pass and high pass work like a tolerance, with a smooth blend in between.  The high pass controls how smooth the transparency falloff will be, while low clip controls the base line of how much of the color will be transparent.

Moving High pass all the way to the left will remove all brush transparency.

Invert key reverses the effect of the key.

Use alpha if active will bypass the regular keying process when you pick up a custom brush, and will use the alpha channel 'selection' for transparency instead.  You can still re-key the brush later.

You can even pick up a brush of an animation by holding the alt key when using the brush selector (when your working on an animation)
 

If your brush has a key (a transparent area) it will be saved out as the alpha channel in the file when you save the brush

  More High pass.  Low clip.

Here, the flower was 'selected' with the lasso alpha tool, and copied with 'use selected as brush'.  A drop shadow was added so it would stand out.
 

Once a brush is created, it may be selected from the bottom of the brush images panel.  Although, it is often enough just to switch back to using a custom brush.  A custom brush stays in memory until you free it or make another one.

Storing a custom brush with "store" under the brush menu lets you keep a copy or multiple copies of your image in memory, then do things to it as you work, like changing the hue/sat/value of the brush. You can also build an animated brush (a brush with multiple images that cycle) with the store feature.  See the section on the Brush Manager for more information.

Custom brushes have another trick. They can be either full color, or work like a regular (8 bit) brush. The modes are called Color (F1) and Matte(F2).

 You can also change the setting under the brush menu/style. When working in Matte style, the color of the brush is determined by the primary color when painting with the left button, and the secondary color when painting with the right mouse button.

Working with custom brushes in matte mode is just like working with internal brushes in that you work with the primary and secondary colors.  Should you need to swap the primary and secondary colors on the tool panel, you can do so with drag and drop

While in Matte mode, you can use the same brush as a more traditional tool to spread paint around...

See the section on the brush settings panel for more information.

Loading and Saving brush's is a quick and easy way to work with multiple images without destroying your buffer.  You can load in an image as a brush and stamp it down on your buffer, or your swap buffer, then pick out parts of it you want by selecting a new brush.

You can open a brush in any supported format, by droping down the 'Files of type' control and selecting 'Automatic (60+formats)'

Images that are in 32 bit format will use the alpha channel as the brush's key (or transparency channel)

When saving a brush image, you can save in a number of formats by clicking on the 'Save as type' dropdown control.

Brushes are always saved in 32 bit format and include an alpha.  The alpha is taken from the brush's key (or transparency channel)

The Media manager can be used to store your brush settings, no matter which brush type you are using. If you're using a custom brush, then the image is stored with the settings. If you're using an internal brush, then the index of the brush is saved with the settings.

Clicking on the button lets you save your current brush, with all its settings to a file.  The button lets you remove the currently selected file from the list.  This deletes is file.

Any brush type you are using can be saved with the Media Manager.  This includes the AA Pen, Internal brushes, and Custom brushes.  If a custom brush is in use, it's image is saved with the file.  If an internal brush is in use, it's index is saved.  Changing brush sets will thus have an effect on media in the Media Manager.  Currently, animated brushes are not saved by the Media Manager.  Only the current brush image will be saved, just like a custom brush.  Should you want to, you can convert an internal brush to a custom brush by a menu item on the Media menu.

Clicking the 'allow custom brush transforms' lets you apply dynamic effects to a brush like random scale and random rotation from the brush settings panel.  See the section on the brush settings panel.

  All of the effects that are available for internal brushes are then available for custom brushes.  It's not always desirable to have this on;  when you just want to move an image from one place to another, for example, but it can be a real boon for varying objects in size, color, and placement.

  Note that with this option, changing the Size scroller on the tool panel will now control the overall size of your brush.

You can create a seamless image by picking it up as a brush and applying "Make seamless" from the brush menu. If you wanted to make a seamless texture for a 3d program for example, you could do that, then save out the brush. It's exactly the same as saving out a regular image.

The trim scrollers let you select the percentage of your brush or image to blend together.  These sections are then trimmed as the seams are pulled together.

'Keep original size' keep the brush, or buffer, from being changed to a new size.  Instead, the image is scaled to account for the trimming, and the width and height of the brush of buffer stays the same.

If you want to test your seamless image, select Fill Pattern on the gradient/fill panel and press 'q' to fill your buffer with the pattern.  Be aware that It will use whatever fill settings you have active.  If you don't want to destroy your buffer, you can also preview smaller patterns right on the gradient/fill panel by clicking on the brush preview area to the right.  It will expand to fill the entire panel with a preview of your brush.

Everything you can do to brushes from the brush menu, you can also do to animated brushes. With animated brushes, you also have several new options, like applying fx filters to them like an animation.  See the section on animated brushes for more information.

  Once defined, a custom brush can be used as a fill pattern with either the fill tools, or the paint tools.  See the section on fill tools for more information.

Painting with an internal brush, with the drawing mode set to pattern.  The pattern is defined by the current custom brush.