Edible oil is its own packaging problem: the product wets the thread, the consumer pours repeatedly, and the cap has to reseal cleanly without drips. Two neck families cover almost every oil bottle, and the closure choice matters as much as the neck.
29/21 — the standard oil neck
For 750 ml and 1 L retail oil bottles, the 29/21 neck is the workhorse. Delta supplies it across a 17.6–29 g preform range, so you can right-size the bottle to the fill volume and lightweight where top-load allows.
42/36 — large format & jerry cans
For 5 L catering and jerry-can formats, the wider 42/36 neck handles the higher flow rate and heavier fill, on an 80–84 g preform. The larger bore makes fast filling and clean pouring easier at volume.
1-piece vs 2-piece closure
- 1-piece (LDPE) — a simple screw cap: lowest cost, robust seal, fewest components. The default for most oil bottles.
- 2-piece (HDPE + LDPE) — adds an LDPE pourer / flip-top insert for controlled, drip-free dispensing — the premium retail experience.
The 2-piece reseals more cleanly for repeated kitchen use; the 1-piece wins on cost and simplicity. Both fit the 29/21 neck, so you can change the consumer experience without re-tooling the preform.
Specify it right
Match the fill volume to the neck and weight, then pick the closure to the brand experience. Filter the oil range by neck and weight in the Product Finder, compare the closure materials, and drop your choice into the Smart RFQ Builder. Delta El Nile for Industry will confirm the neck, preform weight and closure against your line.