: Thanks everyone, especially Paul J for his epistle :-).
: I know all the arguments, but I like the look of finger joints and
: hadn't done it, nor could I remember anyone ever having done it
: or having discussed it.
.................
: John

I suspect the main reason for developing the finger joint was to reduce waste in factories. At industrial levels the machinery and tool costs pay for themselves.

I use a thickness scarf on strips after they are cut; I find I can get away with 6:1 or even 4:1 (if the plank will be almost straight) which wastes very little. I have done tests and found scarf ratios down to 3:1 work fine but I like a bit of a safety factor. The only reason to use longer scarfs is to avoid the pieces sliding apart with clamping pressure due to the slippery glue: I have a small jig that holds them in place during clamping for the few minutes it takes for the glue to grab. By the time I cut the next pair the last plank can come out of the jig so I can do another.