Ah, so interesting! I actually looked this up; have a look at this on English Stackexchange (not the greatest reference, I know): https://english.stackexchange.

Ah, so interesting! I actually looked this up; have a look at this on English Stackexchange (not the greatest reference, I know): https://english.stackexchange.com/questions/159821/what-do-people-mean-or-think-they-mean-by-not-to-scale https://english.stackexchange.com/questions/159821/what-do-p... It looks like some people interpret it as "not exact size" as well. For some reason, that's the context I got from this phrase. I can't remember where I first heard it though. Having said that, if I step back and have a look, "not to scale" does seem to imply not exact proportion, which isn't right either.