A coated optical fiber includes an optical fiber; and a primary coating encapsulating the optical fiber, the primary coating having an in-situ modulus of about 0.12 MPa or less at a thickness of about 32.5 μm, a Young's modulus as a cured film of about 0.7 MPa or less, and a Tg of about −22° C. or below, wherein the primary coating is the cured reaction product of a primary curable composition having a gel-time ratio relative to C1 of less than about 2.