5 Matching Annotations
  1. Jul 2025
  2. Mar 2025
    1. A furtherrefinementinmaking two-colourribbonsisthe useofacentreliningmachine, which automatically drawsathininsulatinglineon theribbon.A transparentgumsolutionispumpedbyairpressure througha stainless needle whichpreventsthecolours from running.

      Center lining machines are used to make bichrome typewriter ribbon. It operates by drawing an insulating line on the ribbon and transparent gum solution is pumped through a needle using pneumatic pressure to keep the two colors from running into each other.