tulle or bobbinette?

Getting a couple of the CA Sunbounce reflector setups, they suggest using their tuning clips to attach tulle or bobinette fabric to tone down the silver or gold sides when you want a softer look, are they referring to white or black of these fabrics (netting)? Does anyone know, I suppose I could get both to see what happens.

Either would work, depending on how much you wanted to tone down the light level. Obviously black would reduce the light levels more than white.