- steel crowns with the hightest level of tin plate
- also known as ETP crowns (electrolytic tin plate)
- a shinier finish
- ideal if you are looking for a glossier/premium-looking/bright appearance
- tin-free steel crowns (steel coated coated by chromium)
- a less shiny finish
- ideal for a bold colour
Both E4/E4 and TFS types include oxygen scavenging liners, which have the ability to absorb residual oxygen from the head of the bottle, helping to keep the product fresher for longer.