In this case I just drew lines on it and then set up a temporary jig on the bench. I pinned down the piece and set up two stops top and bottom. Then I used a square offcut of MDF which I clamped in place to rout each flute. I then just moved the square piece and clamped it for each one. I thought about making a dedicated jig but it would have taken longer to make than use this method. HTH. :wink: