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