"Bumpy leather" - Shape brush

0. Define Brush Preset
This brush has a few more settings than the texture brush. We will create it in pretty much the same way as the standard brush in my first tutorial "a rough line". The main thing though is that instead of using a default brush head (brush shape) we will use the pattern we built earlier. Remember the last thing we did in "Preparing a pattern"? Yup, a circle brush shape with a soft edge. To use that now, select the shape (the one with black on transparent) by making a circle around it or CTRL-click (COMMAND-click in mac) the actual layer to select everything in it. Now go to "Edit/Define Brush Preset..." and name the brush.

1. Brush Tip Shape
As we open the custom brush window it will use the shape as your new brush's basic shape. The size will be the amount of pixels your selected image was, but you can easily change that here. As you can see I've chosen to tilt the angle somewhat for a better pattern and change the spacing until the shapes blend nicely into a long consistent stroke.

2. Shape Dynamics
As usual, I do what I always do here: Set the control to "Pen Pressure". The end of the stroke now look much better. Continue with the next step...

3. Scattering
Time to get some irregularity into the brush. Instead of having a straight line of exactly the same pattern, we here scatter the bits around a bit. When you paint there will still be a nice and simple pattern but the shape and fade of it will be much more "noisy" and for now, painting with the brush will make the pattern overlap and very fast turn completely black. We'll get to that.
(More info on scattering in "a rough line".)

4. Dual Brush
We will now shape the line some more by using a dual brush. We select a standard brush head namely "Soft Round" with pixel dimension 200. This soft brush will burn away some of the edges by using the mode "color burn". This head is actually a sort of soft, faded noise, with a low spacing and a very high scatter effect.

5. Other Dynamics
Here we max both values. We do that so that the pattern will shift nicely when we paint it. This way, it won't just be a black and white pattern, but instead an interesting grayscale depending on how slow you you draw your lines and if you return and repaint an area. If you just doodle with a stylus (well, or your mouse), the texture will grow and get darker as you progress. Notice the "Pen Pressure" setting I did here to change the flow. All in all, the stroke will be much thicker if you paint by mouse (compared to a stylus) and you will loose some of the fine control this brush use.

6. Final setting and save!
We will use the airbrush setting as a final touch. You can always activate or deactivate this option in the brush settings (top bar) but save the brush with the setting you enjoy using the most.

And just like that, the second brush is done as well.
Once again, remember to save.

The tutorial would normally end here, but I'd like to show you some additional info on managing and sharing your brushes. Move on to page 3!