Serrated Surface Holds Screen Securely in Frame Economical for Fabricators This Screen Retainer Spline is a high quality, hollow core vinyl used for repairing, re-screening or fabricating window, door and patio screens. Bulk rolls are economical to use and easy to handle. App rox. Le ngt h per Roll: 1140 ft (347.5 m). The gray spline blends well with aluminum or gray fiberglass screen wire and mill colored frames. The black spline blends well with charcoal aluminum or charcoal fiberglass screen wire and bronze colored frames. An easier to handle and smaller 100 foot (30.48 meter) size is also available.