Bamboo Studio 4-1/2-Inch Bamboo Boat, 2-Ounce,Pack of 12, Natural Color Includes 12 of our 4.5-inch bamboo boats We use the outer bark or "sheath" of the bamboo plant, the sheath is collected, steamed, and pressed into shape No dyes are used to alter the color, the bamboo is as close to it's natural form as possible Microwave safe, disposable, may hand wash for extended uses (do not submerge in water), dry immediately after washing Please note that our boats are measured length wise at the top of the boat and that the bottom of the boats taper down in size.