From the Quote Box – Constable

Always remember,sir, that light and shadow never stand still…. In your skies, for instance, always aim at brightness, although there are states in the atmosphere in which the sky itself is not bright. I do not mean that you are not to paint solemn or lowering skies, but even in the darkest effects there should be brightness. Your darks should look like the darks of silver, not of lead or of slate. — John Constable