So, recently, Im testing some different ways to get effects on leather.
Here I made a 1x1cm leather cord, splittet it down to half size, and made a test. Its waaay to pronounced, but it was just a test.

I saw this belt on the web, and loved the raised effect was rounded. I don't know for sure, but it has to have a core right? Its not just skived edges like normal raised belt? And if so, how is the core made. Im thinking of making a U shape grove in a wood block, and hammering down a wet leather strip to round it, but dont know if that the best way
Also thought about trying the way, Phillips shapes the handle in "The Making Of A Post Handle Pt 1/2" maybe a combination

So guys, please come with your valuable input 😁
I am by no means able to comment on this as I'm still learning to thread a needle. However, putting my engineering mind at work, would skiving or sculpting the underside of the top layer help with the forming of the double dip?
Less thickness on the underside along the stitching line, but not to the edge, should then cause the leather to complete the dip and come back to full thickness at the edge thus giving a look that the belt has that you show above. Hope this makes sense...
I also hope I am not confusing things or commenting where I shouldn't :)