With the model still in its foam cradle I have airbrushed some more Sleeper Grime onto the buffer beams. I left it to dry for 15-20 minutes (time for a coffee) and then started to remove the paint with a damp brush. The brush is not dampened by dipping it into thinners, but by placing a couple of drops of thinners onto the bristles with a disposable pipette. The combination of not-quite-dry paint and slightly damp brush gives a lot of control over how much paint is removed. With the use of light pressure on the brush, the paint will be left accumulated around detail but removed elsewhere.