fishing line

Will 17 lb mono cast and lay on the spool better than a 12 lb mono of the
same brand.By casting better I mean less backlashes[ not distance ] .The
reason I ask is that I respooled several reels that had 17 lb on them and
dropped down to 12 lb [same brand ] .I had a busy day picking out
birdnests of gigantic proportions..The reels that weren't respooled worked
like always......
I don't really understand why line size would make that much of a
difference but???