So I've been been trying to figure out lately, how, by sight and touch, to determine which leathers and suede (mostly on shoes) are of higher quality than others. I'm not talking about top grain, full grain, splits, bookbinder, etc., I mean differentiating between two different box calfs or two different suedes. All of the information I have been able to find are on different types of leather. I'm looking for advice on judging two different leathers within the same type. Does anyone have and experience of resources they could share on this? Thanks!