The plurality of linear projections may preferably provide an uneven surface which has a center line average surface roughness Ra of {HEAD ~ 15 300 nm} when scanned in {TAIL ~ a direction} parallel to the linear projections, a center line average surface roughness Ra of 20 600 nm when scanned in a direction perpendicular to the linear projections, and an Ra/Ra ratio of at most 0.8 
The plurality of linear projections may preferably provide an uneven surface which has a center line average surface roughness Ra of { HEAD ~ 15 300 nm } when scanned in { TAIL ~ a direction } parallel to the linear projections , a center line average surface roughness Ra of 20 600 nm when scanned in a direction perpendicular to the linear projections , and an Ra / Ra ratio of at most 0.8
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH