Abstract: A composite tube for yarn winding or the like incorporating a body or base defined by a plurality of spirally wound plies of paperboard or the like, and a structural reinforcement ply about the body. The reinforcement ply, spirally wound in the manner of the body plies, includes adjoining square skived abutting edges forming a continuous spiralled groove which defines the seam area of the ply. A reinforcing and sealing strip is laid as a continuous member within the formed groove, filling the groove and being bonded to all surfaces thereof. The height of the strip is substantially equal to or slightly less than the depth of the groove. The tube is completed by surface defining plies including an inner ply of machine glazed kraft paper and an outer ply of parchment.