That you can use a sharpie to write on them so that people can keep track of their cup. Note: As the product will be gravitationally squeezed during transport, there will be individual cups stuck together, just place them in warm water to separate them. You can use these green plastic shot cups 2 oz as tasting glasses, sample glasses, medicine, toothpicks, condiment containers. Or regular wine glasses for jellies, wines, juices, and other beverages. ideal for catering, celebrations, alcoholic beverage tastings, weddings, picnics, BBQ's, etc. lots of novelty uses. beer pong cups for game parties This 2 oz plastic cup is stackable and no worry about it breaking like glass. ​The strong contrast between the white inside and the bright colors outside will add more liveliness to the party. It's great for cocktail parties, birthdays, graduations, holiday parties and other celebrations.