Guides from the closure floor.
Practical notes on ROPP caps, sizes, wads and terminology — written to help you specify the right closure rather than to sell you one.
ROPP basics
What is a ROPP cap? Roll-on pilfer-proof closures explained
Why a threadless aluminium shell makes a better seal than a pre-threaded cap, and what the pilfer band is actually doing.
Read the guide →Sizing
ROPP cap sizes: 20, 22, 25 and 28 mm, and what fits where
The size on the box is the bottle's neck, not the cap. What each of the four standard sizes is used for, and how to identify yours.
Read the guide →Wads and liners
EPE vs latex wads: choosing the liner that actually seals
The aluminium holds the liner in place; the liner holds the product in. How to choose between EPE and latex.
Read the guide →Terminology
ROPP cap, PP cap, pilfer-proof cap: one closure, several names
Why two quotations for the 'same' cap can be for different products, and how to tell which is which.
Read the guide →