Well, you could prove it by digging up texts and commentaries from the time that mention these devices. Diary entries, etc. It's unlikely that so many masters

Well, you could prove it by digging up texts and commentaries from the time that mention these devices. Diary entries, etc. It's unlikely that so many masters would use this technique without leaving some evidence of it behind. So, in the absence of that kind of evidence, I think it'd be okay to dismiss it as a primary force of innovation during the renaissance, especially if other techniques exist that were more readily discussed.