I understand that I can change brush opacity by typing a number (e.g. typing "2" and "3" in quick succession will set opacity to 23%) and brush flow by pressing "Shift" and typing a number.
But I need to change between two settings for flow and opacity almost every other brush stroke. I want to paint a few lines with flow and opacity at 100%, then some lines with flow and opacity at 33%, then at 100% again. Having to type five keys (or seven, if I want to set to 100%) before I can paint the next stroke is taking more time than the actual painting – and I usually miss the correct keys and have to spend a few additional seconds correcting the faulity settings.
I would therefore like to be able to change both settings with a single click of a keyboard shortcut, and change the settings back with a single click of another.
How can I achieve that?