Transparisteel was a hard and completely transparent polymer. This made it a commonly used material for viewports, and the windows of strongholds, and other buildings where security was a must. In starship viewports, transparisteel could be made photosensitive to filter out bright explosions and intense wavelengths of light. Transparisteel was less structurally strong than its opaque counterpart durasteel. Lommite played a major part in making transparisteel.