what's the difference between armet and closed helmet?? I often see both terns used interchangeably
this is an interesting but very simple matter!
both armets and close helms were just called armets, but the current split in words is because we use the term close helmet as a historic distinction for how the helmet opens to enclose the head:
the armet has hinged cheeks that open up vertically, the close helmet has a pivot holding the front plate and visor on the back plate so that the helmet opens horizontally.
then we could argue that the close helm is a later design (and was used up until the 17th century) while the armet was already present in the mid 15th century, but the key difference is the opening mechanism.
of course, there are as many designs of both armets and close helmets as there are one piece episodes so the ones I've depicted are very basic examples, but typically all of them are armets if you aren't a museum archiver.
