Thanks Pete,
As there are many different shades of white the one I just completed was a fur lined coat worn by a Mongol. The base is Humbrol leather. The leather is then lightened with white and softly drybrushed. There are several drybrushings of this mixture with each one having added another drop or two of white where the very top of the fold is almost pure white. A large expanse of white, like a knight's tunic would be approached in another way and I would start with a light gray blended with datk gray (deep folds) and white for the top of the folds. After drying this would be drybrushed several times (allowing each drybrush to dry) with white, each time lessening the pressure used with the brush.