What's the difference between auto-bottom, tuck-end, and seal-end boxes?

Auto-bottom (4-corner-glue) pops open with a locked bottom in one motion — fastest to assemble and holds heavier loads. Tuck-end has folded tabs at top and bottom, cheapest to make but slowest to hand-assemble and lower load rating. Seal-end glue-seals both ends at manufacture — tamper-evident, sealed shut until the customer opens it. Pick based on assembly speed, load, and whether you need tamper-evidence.

When should I use an auto-bottom box?

Use auto-bottom when you assemble in-house at volume (500+ boxes/week), the product weighs over 1 lb, or the bottom needs to lock without tape. Common uses: bakery gift boxes (cupcake, macaron, chocolate), DTC gift boxes, apparel retail, and any mailer that holds a heavier product. Costs ~$0.05-$0.10 more per unit than tuck-end but saves 5-15 seconds per box at assembly.

When should I use a tuck-end box?

Tuck-end is the cheapest and most common — use it for lightweight products (under 1 lb), single-SKU cosmetic and skincare cartons, small food packaging, and any application where per-unit cost matters more than assembly speed. Reverse tuck-end (opposite-side tucks) is the workhorse for cosmetics; straight tuck-end (same-side tucks) is common for retail.

When should I use a seal-end box?

Use seal-end when the box must arrive sealed (retail SKUs at big-box), you need tamper-evidence (OTC drugs, dietary supplements, cosmetics), or the product is small/loose enough that an unlocked tuck flap would let it fall out. Common uses: OTC medicine, dietary supplement cartons, dry food, and cosmetic starter kits.

Which structure is best for OTC drug and pharma packaging?

Seal-end. FDA guidance for OTC drug cartons requires visible tamper-evidence at both ends, and seal-end's glue-sealed closure delivers exactly that — any prior opening leaves a torn or peeled seal that shoppers and retail restockers can see. Add a shrink band around the closure for extra security.

Which structure is best for bakery and food packaging?

Auto-bottom for gift-tier bakery items (cupcakes, macarons, chocolate, cake pops) where load-bearing and fast in-house assembly matter. Standard tuck-end for lightweight bakery items sold at counter (cookies, pastries, bagged snacks). Seal-end for dry food SKUs that ship to retail where tamper-evidence is required.

Auto-Bottom vs Tuck-End vs Seal-End: Which Box Structure Fits Your Product?

By the Custom Box Printing Editorial Team · July 27, 2026

Auto-bottom, tuck-end, and seal-end are the three most common paperboard folding-carton structures used in US custom packaging. Each solves a different problem: auto-bottom optimizes for assembly speed and load, tuck-end optimizes for cost, seal-end optimizes for tamper-evidence. If you're a US brand founder or packaging manager picking a carton structure for a new SKU, this guide walks through the practical trade-offs so you pick right the first time.

Quick comparison

Auto-bottom (4-corner-glue / crash-bottom): Fastest hand-assembly (one motion pops open with locked bottom), holds heavier loads, costs ~$0.05-$0.10 more per unit than tuck-end.
Tuck-end: Cheapest to manufacture, slowest to hand-assemble, lower load rating, ideal for lightweight small-format packaging.
Seal-end (straight-tuck-seal): Glue-sealed at both ends by the manufacturer, delivers tamper-evidence, required for OTC drugs and many retail-shelf SKUs.

Auto-bottom: pop open, lock at the base

Auto-bottom (also called 4-corner-glue or crash-bottom) construction has four flaps at the bottom pre-glued at manufacture. When the flat carton is squeezed open, the bottom locks itself into a rigid base in one motion — no glue-gun, no tape, no manual folding.

When to use auto-bottom

You assemble in-house at 500+ boxes/week (bakery, gift-set assembler, DTC fulfillment).
The product weighs more than 1 lb and needs a locked bottom for transit.
The customer sees the box (a clean locked bottom reads more considered than a taped bottom).
Common applications: cupcake, cake pop, macaron, chocolate, gift boxes, mailer boxes holding heavier products.

Cost and load

Standard auto-bottom in 20pt SBS runs ~$1.15 per unit at 500. Load rating: 3-5 lb comfortably in 20pt SBS, 5-8 lb in 24pt SBS, 8-15 lb in corrugated E-flute. See custom auto-bottom boxes for full specs and pricing.

Tuck-end: cheapest, most flexible

Tuck-end is the classic folding carton — cardstock with folded tabs at the top and bottom that tuck into slits to close the box. Two main variants:

Reverse tuck-end (RTE): Top and bottom tuck from opposite sides. The default for cosmetics, skincare, and most small-format primary packaging.
Straight tuck-end (STE): Top and bottom tuck from the same side. Common for retail SKUs where hang-tab presentation matters.

When to use tuck-end

The product is lightweight (under 1 lb).
Per-unit cost matters more than assembly speed.
The customer opens and closes multiple times (tuck flaps re-tuck; auto-bottom and seal-end are single-open formats).
Common applications: serum, lipstick, lip balm, supplement, cosmetic, ampoule, toner, essence boxes.

Cost and load

Standard reverse tuck-end in 18pt SBS runs ~$0.85-$1.05 per unit at 500 depending on size and finishing. Load rating: 0.5-2 lb comfortably in 18pt SBS, 2-4 lb in 24pt SBS. See custom tuck-end boxes and reverse tuck-end boxes for full specs.

Seal-end: tamper-evident, sealed both ends

Seal-end (straight-tuck-seal) construction glue-seals both the top and bottom tuck flaps at the manufacturer. The customer opens the carton by tearing along a perforated line or peeling the glue-seal. Any prior opening leaves visible damage — the tamper-evidence signal every regulated category needs.

When to use seal-end

Tamper-evidence is required (FDA guidance for OTC drugs, many food and supplement retail SKUs).
The product must arrive sealed at retail (national-retail shelves at Target, Walmart, CVS).
The product is small or loose (tablets, pills, small hardware) that would fall out of an unlocked tuck flap.
Common applications: OTC medicine, supplement, capsule, softgel, dry food, cosmetic starter kits.

Cost and opening mechanism

Standard seal-end in 20pt SBS runs ~$0.95 per unit at 500. Opens two ways: tear-strip perforation (cleanest, most gift-worthy, +$0.03-$0.05/unit) or peel-away glue-seal (cheapest, most secure, included in base). See custom seal-end boxes for full specs.

Which structure fits your product?

Product	Best structure	Why
Lipstick / mascara / eyeliner	Reverse tuck-end	Lightweight, low cost, multi-open
Serum / ampoule / essence dropper	Reverse tuck-end	Snug bottle fit, low cost
OTC medicine / vitamin bottle	Seal-end	Tamper-evidence per FDA guidance
Cupcake / cake pop / macaron	Auto-bottom	Load-bearing, fast in-house assembly
Chocolate / candy / truffle	Auto-bottom or seal-end	Depends on gift-tier vs retail-shelf
DTC gift box (mid-weight)	Auto-bottom	Locked bottom, fast fulfillment
Small hardware / cosmetic accessory	Seal-end or blister card	Tamper-evidence at retail
Subscription outer carton	Auto-bottom or heavy tuck-end	Load-bearing for multi-SKU kits
Retail hang-tab SKU	Straight tuck-end + hang tab	Peg-wall compatible

All three ship flat

Auto-bottom, tuck-end, and seal-end are all folding cartons — they pack flat in bulk for freight, then fold or lock into shape at assembly. Flat shipping keeps freight cost low regardless of which structure you pick. A US-based printer can ship any of the three to any US state with 2-5 day Ground transit and free shipping.

Common combinations with hang-tab, window, and finishing

All three base structures can add:

Hang-tab at the top for retail peg display — see hang tab boxes.
Die-cut window on any panel with PET film patch to show product.
Foil stamping, embossing, spot UV, soft-touch lamination for premium finish.
Printed insert or divider to hold multiple SKUs upright (e.g. sampler boxes, coffee sample boxes).

How to pick for your product

Weigh the product. Over 1 lb → auto-bottom or corrugated. Under 1 lb → tuck-end or seal-end.
Check for tamper-evidence needs. OTC, supplements, retail-shelf food → seal-end.
Estimate in-house assembly volume. Over 500 boxes/week → auto-bottom saves 5-15 seconds per box.
Decide on retail context. Peg wall → add a hang-tab to a tuck-end or seal-end.
Request a 3D mockup. A US-based printer builds all three dielines free — see one in the format you're considering before you commit.