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

The are also available on the context strip for the natural media painting tool. 

There are 3 primary brush types in PD Pro: Internal, Custom, and the Ant-aliased Pen. In most ways, these brush types can often be used interchangeably, however each type has it's own unique advantages.

  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.

Undesirable Segmentation of Lines...

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 image.  This can result in unpleasant line segmentation.

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

Like any of the brush types, you can can draw with the AA Pen, or you can use it with the unfilled rectangle and ellipse tools, the line tool, and the arc tool.

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.

Brush shapes can be accessed by clicking on the “Images” button on the context strip for tools that use natural media.

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.

Brush Sets

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.

You can create brush sets or your own too.

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.

Should you want to, you can convert an internal brush to a custom brush with this menu item on the media presets menu.  Pop up this menu by right clicking on the Natural media tool, or middle mouse clicking on your image.

  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.

Activate the brush keyer by right clicking on the brush selector tool.

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.

Note: Picking up a brush using the right button causes the original to be erased to the secondary color

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

  No High pass.    Some high pass. 

  More High pass.  Low clip.

Another way to pick up a brush is to select what you want with the alpha tools, then choose 'use selected as brush' under the brush menu.

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.
 

What if you have switched to another tool or brush type and want to get your custom brush image back at some point.

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.

Color and Matte mode

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

Each mode has it's own unique capabilities.  For example, in color mode, you can transform the hue, saturation, and value of a brushes bitmap...

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.

You can also make use of the various drawing modes, Default, additive, multiply, etc. just like you can with internal brushes.  For example, you could pick up an image of stars and stamp it down in additive mode a couple of times to make a dense star field, where the stars get brighter where they overlap.

There are some Post Process filters that can be used with a Custom brush. They include things like automatically creating a drop shadow, or an emboss effect. They only work with custom brushes.

After you have a brush, you have loads of things you can do with it. you can scale it, rotate it, change it's colors, store it for later (and store multiple brush images at the same time) You can save the image by itself (save under the brush menu) or save the brush with all its settings with the media browser.

To open the Media Browser, click the button on the context strip for tools that use the natural media tools, such as the paintbrush.

.The Media Browser 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.

Click the pencil icon to save a media. That includes your current brush image and all its settings.

Click on the folder icon to create a folder to organize your media in new categories.

Saving a brush is simple.  Just click the 'Save' menu item under the brush menu.  Saving the brush is really no different than saving an image, except the size and imagery is that of the brush.  No extra information is saved, like brush settings.  If you want those settings, you can save them with the Media manager.

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

You can open a brush in any supported format, by dropping 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' drop-down 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 was the original means of managing media in the program, and it still may find usefulness, such as being able to display some information about a media file, in addition to seeing its preview in full size.

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. Should you want to, you can convert an internal brush to a custom brush by a menu item on the Media menu.

Transforming a brush as you paint.

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 slider 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 slider 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 image, 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 stays the same.

If you want to test your seamless image, select Fill Pattern on the Fill panel and press 'q' to fill your image with the pattern.  Be aware that It will use whatever fill settings you have active.  If you don't want to destroy your image, 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.

Animated Brushes.

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.

Brushes as patterns.

  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.