Why does everyone say 'ligne claire'?

Herge's style was 'ligne claire'. Only once, in 'tintin, the pocket essential' did I see it called 'clear line'. If this is an English forum, shouldn't it be called 'clear line'.

It gets called ‘ligne claire’ because it's a Franco-Belgian tradition. ‘Clear line’ is fine too but it doesn't really matter what you call it, as long as everyone understands it, n'est pas?

It's the name of the style, like the technique "chiaroscuro." People don't translate that as "lightdark," but that's what it means. The name just stuck.

I think I tend to say 'clear line' when talking specifically about the style, and 'ligne clair' when referring to the tradition. But I expect I mix them up when just blurting out with no thought (standard procedure).