The effect of this additive is highly dependent on the type of paper being used. It should only be used extremely sparingly even with 1+4 dilutions. All papers exhibit grain clumping in the shadow area to some extent.
Oriental paper react with a changing image tone which accentuates the grain, with warm tone papers the effect is much less obvious. Using too much solution results in the Lith colouring being suppressed but with the deepest blacks being brought out.