lackering

If a colour be not extremely permanent, dilution will render it in some measure more weak and fugitive; and this occurs in several ways -- by a too free use of the vehicle; by complex mixture in the formation of tints; by distribution, in glazing or lackering, of colours upon the lights downward, or scumbling colours upon the shades upward; or by a mixed mode very common among the Venetian painters, in which opaque pigments are combined, as umber and lake.

Field's Chromatography or Treatise on Colours and Pigments as Used by Artists George Field