: Sould I buy vertical grain lumber or flat grain?

: Does it matter?

Besides appearance, vertical grain, or quarter-sawn, wood is desirable for its dimensional stability. Wood shrinkage occurs tangentially to the growth rings. A plain sawn board will shrink mostly in width. The shrinkage (and expansion) in vertical grained wood will be in the thickness - not width. A foot-wide section of flat grained strips might move 1/4 inch; the same rate in vertical grained would change the thickness of a 1/4" panel by less than 5 thousandths. But a lot of this shrinkage info. is moot for our purposes. Epoxy encapsulation drastically reduces moisture fluctuations which cause shrinkage and expansion.

I'm no engineer and can't comment on the bending forces that apply to a paddle. In terms of hardness, which is probably related, I think of a baseball bat. With the label up, the bat hits the ball with the vertical grain where the early/late (soft/hard) bands alternate. The label facing the side will present a more uniform surface. The thicknesses and relative hardness of the bands vary a lot with species and growing climate. The ball seems to travel the same either way. I'd go with what looks good.