Page 161 - Photoshop for Lightroom Users – Scott Kelby 2nd Edition

The next slider down, Cleanliness, controls the detail (in fact, they could have named it the Detail slider and saved us a lot of grief). If you want the brush
to paint your image with a cleaner, more detailed look (more realistic), keep this slider closer to the left, and for a softer, more painterly look (seen here),
drag it to the right (I dragged it over to 8.2).

Step Four:
The Scale slider controls the size of your brush, so dragging it way over to the left paints your image with a very thin brush and dragging it all the way over
to the right paints it with very thick strokes, which definitely creates a different look. In short, want the look of bigger brush strokes? Drag the Scale slider
to the right (compare the sky in this image with the image in Step Three, and you’ll see the difference in stroke size).