The carton style is the single biggest structural decision after size. For most retail and DTC products you're choosing between three closures: straight tuck end (STE), reverse tuck end (RTE) and an auto-lock bottom (AB, also called crash-lock or snap-lock bottom). STE is the simplest and cheapest; RTE is the most common retail default; AB is stronger and faster to erect on a line but costs more per unit. Lock the style before the dieline, because the closure changes the blank layout, the artwork and your filling speed.
The closures you'll actually be offered
When a supplier asks "STE or RTE?" they're asking where the tuck flaps land, not which board you're using. The European Carton Makers Association's ECMA code is the formal reference for these constructions, and EN 14054:2003 standardises the basic carton types in carton board.
Straight tuck end (STE)
Both tuck flaps fold to the same face of the carton. It's the simplest blank, easiest to hand-erect and the lowest-cost closure to tool. Use it for light, low-stress products — apparel, cards, small personal-care items — where no one is relying on the bottom to hold weight.
Reverse tuck end (RTE)
The top tuck folds to one face and the bottom tuck to the opposite face. It looks cleaner on shelf (the exposed tuck stays on one side), erects by hand just as easily and holds slightly better than STE. This is the default retail carton for food boxes, personal care and supplements.
Auto-lock bottom (AB / crash-lock / snap-lock)
The bottom panels arrive pre-glued in a folded position, so the floor locks flat when the carton is squared up. The result is a stronger floor and much faster erection on a filling line — but a more complex die-cut and an extra gluing step, so it costs more on short runs. It's usually paired with a tuck top for reclosure.
Seal-end (glued top and bottom)
No tucks at all: both ends are glued shut on the line. Tamper-evident and hygienic, so it's the standard for pharma and some food — but it offers no reclosure.
Other styles worth knowing
- Tuck-top auto-bottom — the AB carton with a tuck top; the practical default when you want a locked floor plus reclosure.
- Window carton — any of the above with a film patch so the product shows through.
- Sleeve and tray — two-piece or glued structures for heavier or premium goods, moving toward rigid boxes.
- Display / five-panel — for shelf trays and counter displays.
How style changes cost, speed and freight
| Style | Floor strength | Filling speed | Blank/tooling cost | Typical product |
|---|---|---|---|---|
| Straight tuck (STE) | Low | Hand only | Lowest | Apparel, cards, light retail |
| Reverse tuck (RTE) | Low–medium | Hand / simple line | Low | Food, personal care, supplements |
| Auto-lock bottom (AB) | High | Fast (auto) | Medium–high | Cosmetics, electronics, heavier goods |
| Seal-end | Medium–high | Fast (auto) | Medium | Pharma, tamper-evident food |
| Tuck-top auto-bottom | High | Fast | Medium–high | Reclosable heavier retail |
Three effects show up in your quote:
- Blank and tooling — a glued auto-bottom needs a more complex die-cut and a pre-fold/glue step, which raises setup cost most on short runs. STE and RTE are the cheapest to tool.
- Filling labour — STE and RTE are hand-erected; AB and seal-end are built for machine erection. If you're hand-filling a few thousand units a month, an auto-bottom may cost you more than the extra strength you actually need.
- Freight — the closure itself ships flat, but the style interacts with your outer carton. Right-sizing the outer carton to the actual product usually saves more freight than switching closures.
What to send so the dieline comes back right
Send these in the first request and a supplier can return a workable dieline instead of another round of questions:
- Internal dimensions (L × W × D) and product weight — measure the product, not an old box
- Chosen style (STE / RTE / auto-bottom / seal-end), or the loading method if you're unsure
- Board grade and caliper — or "recommend for weight and size" (see the board grades guide)
- Print sides, colour count and finish (matte, soft touch, foil, emboss, window)
- Quantity and destination market
- Any compliance documents you need — food-contact or FSC scope, which Foldveil verifies per factory, material and production run
Where board grade and print fit in
Style is structure; board grade is material. The paperboard grades guide covers SBS, FBB, CRB and CUK and how to pick caliper for your product weight — read the two together. Print method is a separate choice driven by run length and colour work; the printing methods guide explains the trade-offs.
If the product and budget are pushing you toward a heavier, more premium structure, a rigid box may fit better than a folding carton — the folding cartons vs rigid boxes comparison covers unit cost, freight and unboxing.
To get a quote on any of these styles, send width × height, quantity and style through the RFQ form.
FAQ
What's the difference between a straight tuck and a reverse tuck carton?
In a straight tuck end (STE) both tuck flaps fold to the same face of the carton; in a reverse tuck end (RTE) they fold to opposite faces. RTE is the more common retail default because it keeps the exposed tuck on one side of the shelf.
Which folding carton style is cheapest?
Generally straight tuck, then reverse tuck, then auto-lock bottom. The pre-glued auto-bottom adds a die-cut and gluing step that raises setup cost most on short runs.
Is an auto-lock bottom worth the extra cost?
If you machine-erect, or the product is heavy enough that a friction tuck would give way, yes. For light hand-packed items the extra floor strength is usually not worth the added cost.
Can I add a window to any carton style?
Yes — a window patch is a finishing step rather than a structural change, so it can be added to tuck-end and auto-bottom cartons alike.
Do I need to pick the style before artwork?
Yes. The closure changes the blank layout, so the dieline should be locked before artwork is placed.