Project PET Wine Glass

Designing for the future - Cap Lining Retaining Rings

While the above diagram is suitable for the top of the range Ztab foam backed liner; this design will likely suit most variations of cap lining material on the market.
Incorporating this kind of forethought and design into your cap makes it a cap available to a lot more applications.
This design means that the lining material will not need to be friction fitted or glued in place.