Loading paint on brushes...

Dear Painter Community,
I've started using Corel Painter X3 recently, and I think it's a great program. There's one function regarding brushes I would like to change.
When painting with real paint, an artist will dab a brush in paint and then apply it to the canvas. The artist would not reload a brush with after every brush stroke – he/she would work the paint already on the brush to draw/render, or shade. Painter, however, reloads paint on my brush loads with every new stroke. The result is that I end up continually darkening an area past its intended value.
Is there any way to change the default brush behavior in Painter so that it doesn't automatically reload paint? I've scoured the user guide and searched online for an answer to my question, but I haven't found anything.
Any advice or suggestions are greatly appreciated!
Thanks!
Pietro