How about if you say "settecento"? Maybe it is a new confusion that they drop a thousand years, and maybe it would imply Italian art specifically.
(This Xth century business always bothered and genuinely confused me to no end and everyone always dismissed my objections that it's a confusing thing to say. I'm a bit surprised, but also relieved, to see this thread exists. Yes, please, kill all off-by-one century business in favor of 1700s and 17th settecento or anything else you fancy, so long as it's 17-prefixed/-suffixed and not some off-by-anything-other-than-zero number)
Hope this clarifies. Not to miss the forest for the trees, to reiterate, the main takeaway is that it may be better to define and use a specific tag to pinpoint a sequence of events in a given period (e.g. settecento) instead of gesturing with something as arbitrary and wide as a century (18th century art).
And Italian people in general.