A cross sectional shape of {HEAD ~ each striation} is an isosceles trapezoid having {TAIL ~ an upper base} at the face side and a lower base at the back side of the golf club head 
A cross sectional shape of { HEAD ~ each striation } is an isosceles trapezoid having { TAIL ~ an upper base } at the face side and a lower base at the back side of the golf club head
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH