50 ml bottles are easy to use. The majority of them can be fired to cone ten and also work at cone 06. They require a clear glaze and firing to appropriate temperature. Colours are food safe, cleanup with water is exceptionally easy and they start at $7.25 Canadian dollars each. Colours are bright and mixable. The 250 ml size starts at $14.25 Canadian. 500 ml size starts at $23.95.