Etu Black Colorblock Mason Jar SmallEnhance Your Home With An Etu Black Colorblock Mason Jar Small Etu's collection of Colorblock Mason Jars are steeped in history and made from recycled glass collected from around Central Europe. Mouth blown into vintage inspired casts to retain their old world appeal, they have added a bold splash of high gloss black paint to the bottom of these canning jars to give a contemporary element to the once rustic vessel. Once used for preserving fruits and