An optical-fiber ribbon, comprising: (i) a plurality n of respectively adjacent optical fibers extending in a longitudinal direction and arranged in parallel to form an optical-fiber assembly having a width w extending crosswise to a longitudinal length of the optical-fiber assembly; and (ii) bonding material on the optical-fiber assembly adhesively bonding adjacent optical fibers in the optical fiber assembly, the bonding material repeatedly forming alternating first and second bonding-material patterns across the optical-fiber assembly for a portion of its longitudinal length, wherein, in the same direction along the longitudinal length of the optical fiber assembly: the first bonding-material patterns extend across the optical-fiber assembly from a first outermost optical fiber in the optical-fiber assembly to an opposite second outermost optical fiber in the optical fiber assembly, and the second bonding-material patterns extend across the optical-fiber from the second outermost optical fiber in the optical-fiber assembly to the opposite first outermost optical fiber in the optical-fiber assembly, the alternating first and second bonding-material patterns have respective mean lengths l1 and l2 as measured along the longitudinal length of the optical-fiber assembly, and the alternating first and second bonding-material patterns achieve recurring adhesive free gaps in which no bonding material is present across the width w of the optical-fiber assembly for a portion of its longitudinal length, the adhesive-free gaps having a minimum length g as measured along the longitudinal length of the optical-fiber assembly, characterised in that g ≥ 8 × (l 1 ÷ n) if l1 ≤ l2 and g ≥ 8 × (l 2 ÷ n) if l2 ≤ l1, preferably wherein g ≥ 16 × (l1 ÷ n) if l1 ≤ l2 and g ≥ 16 × (l2 ÷ n) if l2 ≤ l1, more preferably wherein g ≥ (l1 + l2) × (n = (n-2)). (i) a plurality n of respectively adjacent optical fibers extending in a longitudinal direction and arranged in parallel to form an optical-fiber assembly having a width w extending crosswise to a longitudinal length of the optical-fiber assembly; and (ii) bonding material on the optical-fiber assembly adhesively bonding adjacent optical fibers in the optical fiber assembly, the bonding material repeatedly forming alternating first and second bonding-material patterns across the optical-fiber assembly for a portion of its longitudinal length, wherein, in the same direction along the longitudinal length of the optical fiber assembly: the first bonding-material patterns extend across the optical-fiber assembly from a first outermost optical fiber in the optical-fiber assembly to an opposite second outermost optical fiber in the optical fiber assembly, and the second bonding-material patterns extend across the optical-fiber from the second outermost optical fiber in the optical-fiber assembly to the opposite first outermost optical fiber in the optical-fiber assembly, the alternating first and second bonding-material patterns have respective mean lengths l1 and l2 as measured along the longitudinal length of the optical-fiber assembly, and the alternating first and second bonding-material patterns achieve recurring adhesive free gaps in which no bonding material is present across the width w of the optical-fiber assembly for a portion of its longitudinal length, the adhesive-free gaps having a minimum length g as measured along the longitudinal length of the optical-fiber assembly,