What is this “scratch” that you make things out of, anyway? Apparently the expression derives from a sporting term, referring to “a competitor who receives no odds” (which, in my dim understanding of this sort of situation, is a good thing). The OED defines “from scratch” as “from a position of no advantage, knowledge, influence, etc., from nothing.” So… exactly what I said it didn’t mean. Never mind. Actually, a better expression for what I’m talking about would be “from whole cloth.” The OED doesn’t have anything to say about that one, but I’m going to go out on a limb and assume that it has to do with sewing.