Overview & Specifications
What Is a Snap Lock Box?
A snap lock box, often called a 1-2-3 bottom or lock bottom carton, is a paperboard folding carton whose bottom is closed by folding its bottom flaps in sequence so they overlap and lock together. Unlike an auto lock box, nothing at the base is glued in production; the packer forms the lock when setting up the carton, then fills it and closes the tuck top.
How the 1-2-3 Bottom Locks
The base forms in a short folding sequence.
01
Fold in Order
The bottom flaps are folded in the order set on the dieline, each one positioned for the next.
02
Interlock
Cut tabs and slots on the flaps engage as the last flap goes in, so the flaps hold each other closed.
03
Tuck Top
After filling, the top closes with a tuck flap and dust flaps.
Anatomy of a Snap Lock Box
01
Bottom Flaps
Fold in sequence to form the lock.
02
Lock Tabs and Slots
Set on the dieline so the flaps engage.
03
Side Seam
Glued in production.
04
Tuck Top
Re-openable closure.
05
Main Panels
Front, back and side print surfaces.
The base is built from overlapping flaps, so keep bottom artwork to a simple mark or barcode area set on the dieline.
Snap Lock vs Auto Lock at a Glance
| Feature | Snap Lock | Auto Lock |
|---|---|---|
| Bottom made | Folded by the packer | Pre-glued in production |
| Bottom setup | Several folds in sequence | One motion as the carton opens |
| Production glue at base | None | Yes |
| Bottom setup at packing | Flaps folded and interlocked by hand | Forms on opening, no bottom folding |
Application guide
When Is a Snap Lock Box the Right Choice?
A snap lock box suits products that call for a dedicated locked base, where hand-folding the base fits the packing workflow, such as bottles and jars, personal care, small hardware and accessories, candles and small vessels with inserts, and general retail goods.
01
Dedicated
Dedicated Interlocking Base
The interlocking flaps form a locked bottom instead of a tuck flap; suitability depends on board, dimensions and packed weight.02
No
No Pre-Glued Base
The base is made by flap design alone, so no production glue is needed at the bottom.03
Flat-Ship
Flat-Ship Folding Carton
The carton still ships and stores flat until it is set up for packing.04
Alternative
When Another Format May Fit Better
If bottom setup time matters across many cartons, an Auto Lock Box forms its base in one motion. For light products, a Reverse Tuck Box or Straight Tuck End Box is simpler, and a Seal End Box closes with peel-and-seal ends.
Snap Lock Box Specifications
Custom snap lock boxes are specified around the interlocking bottom, carton dimensions, board grade and caliper, top closure, inserts, print coverage and finishes, with flap order and lock geometry set on a custom dieline for each size.
| Specification | Available Configuration |
|---|---|
| Product Type | Folding carton with interlocking 1-2-3 bottom |
| Category | Tuck Boxes |
| Dimensions | Custom inside L × W × D, built around the product and base load |
| Core Construction | Glued side seam, interlocking snap-lock bottom per approved dieline |
| Top Closure | Tuck flap with dust flaps, or other compatible top |
| Board | White SBS, kraft or recycled paperboard; corrugated board; metallic, holographic, pearlescent or textured cardstock |
| Board Caliper | Paperboard from about 14 pt to 28 pt, or E-, F- or B-flute corrugated; matched to the product |
| Inserts | Paperboard, foam/EVA, molded pulp or thermoformed PET/PVC |
| Add-ons | Die-cut window (with or without film), hang tab, tongue lock, tear strip, plastic handle |
| Print Coverage | Exterior only, exterior + interior, or full inside and outside |
| Print Methods | Offset, digital, UV or screen printing; CMYK and Pantone spot colors |
| Coatings and Finishes | Matte, gloss or soft-touch lamination, aqueous or grease-resistant coating, foil stamping, emboss/deboss, Spot UV and raised 3D UV |
| Starting Price | From $0.85 / unit; final price depends on size, board, print, finishes and quantity |
| Minimum Order | 500 units |
| Standard Production | 7 days from approved proof |
| Rush Production | Available on request |
| Shipping | Ships flat, USA and worldwide |
How Snap Lock Compares to Other Tuck Box Structures
| Attribute | Snap Lock | Auto Lock | Reverse Tuck | Straight Tuck End | Seal End |
|---|---|---|---|---|---|
| Bottom | Hand-locked flaps | Pre-glued, forms on opening | Tuck | Tuck | Peel-and-seal |
| Production glue at base | None | Yes | None | None | Adhesive strip, applied in production |
| Bottom closure | Hand-folded interlocking lock | Pre-glued automatic lock | Tuck flap | Tuck flap | Peel-and-seal |
| Bottom steps at packing | Several folds | One motion | Tuck in | Tuck in | Peel and press |
| Best fit | Hand-locked base, no pre-glue | Repeated packing, fewer bottom steps | Everyday re-openable cartons | Front-led retail | Closed until opened, no glue |
What Size Snap Lock Box Do You Need?
Give the inside length × width × depth: length and width describe the opening under the tuck top, and depth runs from that opening down to the locked base. The bottom flaps are sized from length and width, so the lock geometry is drawn for each size rather than scaled from another carton.
How Product Size Becomes Carton Size
The figures below are planning references, not fixed manufacturing rules; final allowances depend on product shape, insert and board.
| Step | Typical Allowance |
|---|---|
| Product to inside length and width | Add about 1–2 mm (1/16 in) |
| Product to inside depth | Add about 2–3 mm for the tuck top and locked base |
| With an insert | Size to the insert's outer dimensions |
| Inside to outside | Each dimension grows by about two board thicknesses |
Paperboard Caliper Reference
| Board | Typical Thickness | Typically Suited To |
|---|---|---|
| About 16–18 pt | About 0.41–0.46 mm | Medium-weight personal care and accessories |
| About 20–24 pt | About 0.51–0.61 mm | Bottles, jars and heavier retail contents |
| About 26–28 pt | About 0.66–0.71 mm | Larger hand-packed cartons |
| E- or F-flute corrugated | About 0.8–1.6 mm | Heavier products or extra edge strength |
| B-flute corrugated | About 3 mm | Large or multi-unit cartons |
Important: Treat these values as references. A thicker board makes bottom flaps stiffer to fold and lock, so board and lock geometry are confirmed together on the dieline, and no weight rating is given without testing.
If you are unsure, share the product dimensions and weight with the quote request, and the carton is sized around them.
Why Is It Called a 1-2-3 Bottom?
The name comes from the folding order: the bottom flaps go in one, two, three, and the last flap locks the others in place. The exact order and tab shapes are set on the dieline for each carton size.
