Monday, May 7, 2012
What is skiving, and how do I do it?
First of all, it's pronounced SKIVE-ING, like "driving" and "diving". For the longest time, I thought it was skivving, like - well, I don't know what else sounds like skivving...
Anyway, skiving is the process of trimming the edge of a piece of leather to reduce its thickness. It's kind of a tapered cut, going from the full thickness of the leather to something less than the full thickness at the edge. It's a technique sometimes used to taper the edge of a turned seam, so it can be folded and finished without being too bulky.
I usually skive the front seam on hoods that are made in any sort of heavier leather - as you are more likely to feel those edges on your face if they aren't tapered down.
In order to do this, you either need an expensive machine like the one shown in action here, or a blade with a truly sharp edge. I don't have such a machine yet, so I tend to use razors, scalpels and (my personal favorite) surgical prep blades. They're the best to me for a couple of reasons: They are slightly longer than regular razors, so you have more blade to use before it dulls out, and they come out of the package sharper than any other type of razor I have tried.
Here's a closeup of a raw seam edge: When I've seen people working with a skiving machine, they tend to skive before assembly. But for me it is easier to skive after the seam is joined, as I can control the cut better that way.
The razor (did I mention it needs to be extremely sharp?) is guided at an angle along the seam allowance edge, cutting and tapering the thickness as it goes. It is surprising how quickly the leather wears down the blade - it is very abrasive stuff. But usually I can get through an entire project with one or two blades. Initially it will cut like a hot knife through butter, but you will gradually start to feel more drag as the blade dulls.
When you are done, both sides of the seam should taper gently down in thickness so the inside feels smooth and almost seamless...