“Skiving” is generally seen as a bad thing … “avoid work or a duty by staying away or leaving early“! In shoemaking, however, it is a good thing, which stops sore feet and, potentially blisters. On the right, someone is skiving the edge of a piece of leather with a sharp knife. This means putting a shallow bevel on the edge of the leather so that, instead of having an abrupt edge, the edge slopes. On the left, you can see the effect this has on a seam between two bits of leather (the vamp and the quarter, for example). With unskived edges, the seam creates a ridge or hump that will be (a) unsightly and (b) uncomfortable. Once the edges are perfectly skived, however, you can see that the leather forms a flat sheet with no nasty ridge. In practice, of course, skiving simply reduces the height of the ridge, as some thickness of leather must be left in place to take the stitches (shown yellow here).
It’s all part of what makes the difference between a shoe that is slapped together in an unskilled factory and one where good old shoemaking practice still exists for good reason (e.g. skiving). It may now be helped along by an expensive machine with a skilled operator, but it’s that kind of attention to detail that makes a handmade shoe worth having.