When your making a board bow out of say a two by four from a local hardware store i have seen no mention of following the wood growth rings. do you still have to follow the rings on such a board?? and yes i am a noob at this. the local mega mart hardware store has some really nice select boards that run in price fron 20$ for a 7 foot 1x4 to 30$ 2X4 a couple of the 2X4 have nearly perfectly straight grain with decently wide looking growth rings and no knots.
you can tell wher the saw cut through various rings downt he face of the board and the grain rings range from perfect circles to long V shaped lines all down the face.