I think that must be the case, but in the second graft he's cutting on green wood, and for there to only be cambium exposed there the cut would have to be way shallower and therefore way narrower. Unless the cambium goes a lot deeper than I understand it to go. Maybe that's my problem. When I've cut for a veneer graft I always look for that green line around the edge of the cut and try to line up with that, and getting the cut to be the right size when the rootstock is bigger than the scion is a total PITA. To have only cambium exposed, it seems like you'd have to just scrape the bark away - any flat cut will go past the cambium in the center and leave only the outline cambium around the edges. That's what I've always thought, but apparently I've been wrong, which could partially account for my miserable failure as a mango grafter! I've had success with avocado and citrus, but nada with mango. Since I have to bring the scions a long distance, I know scion viability is probably about 80%+ of my problem. So with the remaining 20% that might have a chance of making it, I want to understand the technique I'm using and do it well. Like I said, since my scions are almost always smaller than my rootstock, veneer seems the way to go.