... (Optional): Acid etch, Decal, Embossing, Engraving, Frost, Plastic(or paper) adhensive labeling, Screen printing. Application: Certificate: ... L) carboy is usually called a jug. A 15 gallon (57 L) carboy is usually called a ... a “demijohn”. It is a glass or plastic vessel used in fermenting beverages such as wine, ... reliable solid glass carboy. Even the best plastic is permeable and if you're purist, ...