Barbour Welting has been around for a long time. Even when I was new to the game it wasn't considered optimal--fine for repair work but not for making. It is spliced, sometimes frequently. It's not unusual to cut a length and find that, no matter how you arrange it, there is no way you can come up with a section long enough to welt a shoe without splices. And the "sections" almost never match in terms of temper or density. One section will be firm enough, the next section basically a rag. I have always cut my own from horse butt or used Baker welting. Traditionally welt was cut from the belly or shoulder of a veg tanned side. But nowadays most outsoling, and esp. shoulder leathers, are not firm enough. Baker might be an exception...since I use the Baker welts already I have never tried. Not that it couldn't happen, but FWIW I've never seen a bonwelt that was, or could have been, captured in a Blake stitch. It is always cemented in (only) and often it is made of plastic.