Pristine? I don’t think the words “pristine” and “custom” go together. Let me check ol’ Webby:
pristine
adjective
pris·tine | \ ˈpri-ˌstēn , pri-ˈstēn, especially British ˈpri-ˌstīn\
Definition of pristine
1 : belonging to the earliest period or state : ORIGINAL
the hypothetical pristine lunar atmosphere
Huh. Well, lookie there. So, another way of saying that might be “definitely not custom”.