Milk-Carton Hypertufas Milk cartons used as molds create cube-shaped hypertufa vessels, each sized for a single succulent. The tint variations are achieved by mixing in masonry stains. Directions Mix 3 quarts peat moss, 3 quarts perlite, and 3 quarts portland cement. Mix in 13 1/2 tablespoons masonry stain (1 1/2 tablespoons per quart). Add water until mixture has the consistency of cottage cheese. Makes 3 to 4 small boxes (4-inch cubes or 4 by 4 by 5 inches).