Many milk glass items crafted from the mid 1800s through the first part of the twentieth century have significant value to collectors. The pieces that were made during World War II also have significant value.
Original labels and makers' marks are frequently absent on milk glass items, leaving their age up to guesswork. Visual clues concerning the possible age of a piece include off-white coloration caused by the presence of crushed bone ash and arsenic in the mixture, a shimmering opalescence and sharply defined mold lines. However, skillful reproductions of old milk glass are abundant in today's marketplace. The value of milk glass items is also dependent on factors such as the general condition of the piece, its overall quality, the pattern and the manufacturer. Price and identification guides are available to help collectors make good choices.