What's the plural form of floss silk? Here's the word you're looking for.
Answer
The noun floss silk can be countable or uncountable.
In more general, commonly used, contexts, the plural form will also be floss silk.
However, in more specific contexts, the plural form can also be floss silks e.g. in reference to various types of floss silks
or a collection of floss silks.
