How can I achieve a wood grain effect

I have only cloned a few photos previously and very new to Painter and I need your assistance.

I have scanned through the brush section of the manual but cannot find a hint to this process. Perhaps it isn't done as I expect.

In the enlarged clip from a painting, I wonder how best to achieve this weathered wood effect.

I see this as a two-coat process. First the solid base colour, then a brush with very dark grey or black, wide spaces bristles.

The example is not ideal, but close enough to explain the effect I am looking for. The very wide and tapered dark areas and knots would be achieved individually.