When shooting for the falling-dominoes effect on the back as well as front side of a saddle stitch, is there any extra benefit to casting to change which thread crosses on top, as compared to placing the second needle through the hole in position so they cross that way?
Put another way: Do you other folks here get better looking slanted stitches on the back side when casting versus putting the front-side needle low in the hole?
It's dazzling---in both "wow!" and "gah, my eyes!" senses---how much information there is to be found on this stuff now. It seems pretty broadly understood, at least practically, that when saddle stitching in slanted holes, changing the direction the threads twist---corkscrew or candy cane, S or Z, standard or reverse thread, right over left or left over right---changes which side gets the shorter, steeper-slanted stitches. Got that.
But as I've been revisiting old notes and doing some experiments on scrap for a new project, I'm seeing what looks like a pattern of better results on the back side with the casting technique. I'm also noticing a preference for casting in the videos and tutorials I've found online, mostly folks focused on wallets, belts, handbag bags, and other small goods, punching pretty wide holes with irons. Coming up on the Stohlmans' book as I did, I'd always just put my "B" needle on one side or the other of the "A" thread in the hole to set the twist. There wasn't a pretty line drawing of throwing any loop over, so I didn't.
I suspect, perhaps naively, that putting needles through the holes to twist one way, casting so they twist the other, and having the thread ride up and over as I pull slack might be slightly reaming the rougher exit side of the holes a tad wider. That might help a bit like how pulling threads taught at an angle can.
That's pure speculation on my part. When I pull slack really slow, to try and see what's going on, results change. I've also tried watching some YouTube videos that show stitching from the back in slow motion, but what I'm looking for is either too small to see or not really there.
Much appreciate any folks taking time to share wisdom or experience!
If I can get to feeling like I've got my head around this last bit, I'll have a nice blog post on twist directions, casting, needle placement, and other tricks, with pictures and tables. Maybe clear the path for those coming behind.