I am really inpired by this style of hatching.
I havn't seen any tutorials or training specifically on the topic of mastering the skill or the method that is supposed to go through your mind when you do so. Plenty of flat hatching or criss cross but nothing on this.
I have found this from American drawing. It doesn't have much technical detail on how this is actually done accept that it's not flat and is curved to infoce form. It compares the two style effects but doesn't ellaborate on the actual method.
I would really like it if sumeone could share their understanding. I have seen this style in some more modern art like some of Loomis and his inspirations and it really does add alot of appeal, even to money. It's one of those styles that you can look at 5000 years from now and still go "woah!"