Other Dynamics

To change our brush opacity and/or flow dynamically as we paint, we use the Opacity and Flow options in the Other Dynamics section of the Brushes panel. Click directly on the words Other Dynamics to access the options:

As soon as you click on the words, the Opacity and Flow options appear on the right side of the Brushes panel. Just as we've seen with other Brush Dynamics categories, each one comes with both a Control option, allowing us to choose from various ways to control the opacity or flow ourselves, and a Jitter slider which let's Photoshop change them randomly:

The Options Bar vs The Brushes Panel
Before you change any of the settings here in the Other Dynamics section, make sure you've set the Opacity and Flow options in the Options Bar back to 100% first, otherwise your results may not be what you expected. The reason is that the Opacity and Flow options in the Brushes panel are directly linked to the ones we just looked at in the Options Bar. If, for example, you've set the Opacity value in the Options Bar to 25%, the opacity of your brush color will never exceed 25% no matter what settings you've chosen with the Other Dynamics options. The same goes for the Flow option.

Opacity Control

To control the opacity of the brush color dynamically as you paint, click on the Control drop-down box directly below the Opacity Jitter slider and choose either Fade, Pen Pressure, Pen Tilt, or Stylus Wheel (if you have an air brush pen). Fade will fade out the opacity of the brush color based on the number of steps you specify and is the only Control option available if you don't have a pen tablet installed (you can still choose one of the other options but it won't actually do anything). I'll select Pen Pressure, since I am using a pen tablet:

With the opacity now being controlled by pen pressure, the more pressure I apply to the tablet with my pen, the more opaque the brush color becomes. Less pressure gives me a more transparent brush color:

Flow Control

The Control options for Flow work the same way. Click on the Control drop-down box directly below the Flow Jitter slider and choose how you want to control the flow from the list. The same options (Fade, Pen Pressure, Pen Tilt, and Stylus Wheel) are available. I'll choose Pen Pressure once again:

When opacity was being controlled by pen pressure, we saw quite a bit of difference between the transparency levels throughout the brush stroke as varying amounts of pressure were applied to the tablet. With flow controlled by pen pressure, we end up with a brush stroke that's darker overall, even with the exact same amounts of pen pressure being applied. Since the brush tips are overlapping, their opacity levels are mixing together, giving us more opaque results than what the same amount of pen pressure gave us when we were controlling the opacity:

Opacity And Flow Jitter

Finally, we can add randomness to the brush opacity or flow (or both at once) using their respective Jitter sliders. The further we drag a slider towards the right, the more variety we'll see as we paint:

Both jitter options will create somewhat similar results, since Photoshop will randomly change the transparency level of each new brush tip. The difference once again is that Flow Jitter will usually give us a darker, more opaque result overall as the opacity levels of overlapping brush tips mix together. Here's a brush stroke with Opacity Jitter set to 100%. The individual brush tips are obvious, but the transparency levels are not affected by overlapping areas:

And here's my brush stroke with Flow Jitter set to 100% (Opacity Jitter has been set back to 0%). This time, we see very few light, transparent areas and many more dark, opaque areas:

And there we have it! That wraps up our look at how we can change and control lots of different aspects of our brushes, from size, shape and texture to color and opacity, thanks to the awesome power of Photoshop's Brush Dynamics!

Missed one of the other Brush Dynamics tutorials? Jump to any of them using the links below:

• Shape Dynamics
• Scattering
• Texture
• Dual Brush
• Color Dynamics

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