Abstract: A golf ball includes an assist mark 10 and a guide mark. The assist mark is straight in plan. The guide mark is distorted in plan. The guide mark is in the shape of an arrow as a whole. The guide mark looks straight to a player swinging a golf club. The player moves the head of the golf club along the direction of the guide mark.

Abstract: A method for printing a marking on a golf ball includes arranging ink in an etching pattern on a printing plate, matching a reference position on the plate to a reference position on the golf ball, transferring the ink from the printing plate to a pad, and transferring the ink from the pad to the golf ball such that the golf ball includes the marking. The pattern includes an etch corresponding to the marking, wherein the etch differs from the marking in a manner dependent on the position of the marking on the golf ball. The marking that results on the golf ball is a linear marking, and a centerline of the linear marking lies entirely within a marking plane that is not a centerline plane of the golf ball, and wherein the edges of the marking are parallel with the marking plane.

Abstract: A sports ball is configured to enhance detection of spin properties by radar. The ball includes a spherical body having a first reflectivity with respect to radiation generated by a radar to be used in detecting spin of the ball. In addition, the ball includes a plurality of markers. Each of the markers has a second reflectivity with respect to the radiation generated by a radar to be used in detecting spin of the ball. The second reflectivity is different from the first reflectivity. The markers are distributed on the ball so that every great circle extending around an exterior surface of the ball is within a distance d of a projection on the exterior surface of the ball of at least one of the markers. The distance d is less than a radius of the ball.