A fairing batten is any material which will bend in a nice smooth curve. For the purpose of drawing forms from offsets, the acrylic spline will probably work well, but it could be a piece of wood or metal as well.

: In kayakcraft, Ted Moores talks about a Fairing batten used for transfering
: plans to wood. Nobody in my area has any idea what this is. I have found
: an Acrylic spline(48"-$10.00) and an acu-curve Acrylic adjustable
: curve (48"-$60.00) We have several acu-curves at work (they call them
: ships curves). But not sure how they'd feel about me borrowing one.