The protective cardboard sleeves that come around disposable coffee cups are technically called zarfs. Zarfs are known by several other names, including Java Jackets™, coffee clutches, coffee sleeves and cup holders. Incidentally, before the cardboard sleeves became known as zarfs, a zarf was a decorative metal holder for a coffee or teacup that didn’t come with a handle.
More about zarfs:
When coffee first became popular in the 13th century, it was served in tiny cups without handles, which were then placed in a decorative zarf to keep the drinker’s fingers from getting burned. Some ancient zarfs were quite intricately carved, and they were often made out of precious metals, rare woods or even ivory.
Making zarfs can be big business — the United Staes alone consumes more than 16 billion cups of takeaway coffee a year, and most of them come with cardboard sleeves.
In Arabic, the word zarf means “container” or “envelope.”