To adjust brush size
Hold down ⌃⌥ and drag the mouse left (smaller) or right (larger).
Or use the [ key (smaller) and ] key (larger).
To adjust brush hardness
| /System/Library/Frameworks/CoreServices.framework/Frameworks/LaunchServices.framework/Support/lsregister -kill -r -domain local -domain system -domain user |
| %w{ a b c d e f }.split("c", "e") | |
| # => [["a", "b"], ["c", "d"], ["e", "f"]] |