Preview image
The real blank at this size, folded by the same engine as the studio. The artwork is a sample from a fictional brand — swap in your own in the editor.
FEFCO 0421Mailer
Large postal box 400×300×150 dieline
B-flute for heavier orders and bundles. A ready-sized preset of the self-locking box with lid — change the length, width and height and every panel, tuck and glue flap is redrawn to match.
Inside400 × 300 × 150 mm
Outside419.2 × 306.4 × 156.4 mm
Flat blank1028.8 × 956.4 mm
Download the dielinePro
Sign in to download. Dieline downloads are part of Pro: PDF, Illustrator, SVG and DXF, cut, crease and bleed on separate layers, without a watermark. See plans
- Reference
- FEFCO 0421
- Inside size
- Length 400 · Width 300 · Height 150 mm
- Size range
- Length 150–600 · Width 80–450 · Height 20–150 mm
- Manufacturing
- 416 × 303.2 × 153.2 mm score to score · inside vs outside sizes
- Parts
- One blank
- Board area
- 0.648 m²
- Default board
- B-flute shipping · 3.2 mm caliper
- Board options
- E-flute KE-flute WB-fluteF-flute
- Good for
The flat dieline
Exactly what the downloads contain, drawn from the template at its default size, with a 3 mm bleed. How to read a dieline.
- Crease
- Cut
- Bleed 3 mm
How the blank is sized
Score-to-score panel sizes of this FEFCO 0421 blank at the default size, with the formula each one follows. L, W and H are the inside dimensions; T is the board caliper (3.2 mm for B-flute shipping). Change the size or board in the editor and every panel is recalculated.
| Panel | Size (mm) | Formula |
|---|---|---|
| Base | 416 × 303.2 | – × W + T |
| Front | 416 × 151.6 | – × H + T/2 |
| Back | 416 × 153.2 | – × H + T |
| Front ear ×2 | 145.2 × 143.6 | – × H − 2T |
| Back ear ×2 | 145.2 × 143.6 | – × H − 2T |
| Left end | 150 × 303.2 | H × W + T |
| Left end roll | 6.4 × 296.8 | – × W − T |
| Left end (inside) | 150 × 296.8 | H × W − T |
| Right end | 150 × 303.2 | H × W + T |
| Right end roll | 6.4 × 296.8 | – × W − T |
| Right end (inside) | 150 × 296.8 | H × W − T |
| Lid | 416 × 298.4 | – × W − T/2 |
| Front tuck | 390.4 × 50 | – |
Adjustable in the editor
Beyond the size and board, this structure exposes 5 options; the template and 3D preview follow each change.
- Front tuck depthmm
- Lock tonguescount
- Thumb notchon / off
- Notch radiusmm
- Lid lock3 options
The self-locking box with lid family
The same structure with sizes, boards and options set for a use.
Preset
Preset
Preset
Preset
Preset
Preset
Preset
Preset
Preset
Preset
Preset
Similar structures
Other structures built in a similar way, matched on code family, category, closures and proportions.
Make this large postal box 400×300×150 yours
Open it in the editor to set your size, drop artwork on each face, check bleed and safe areas, and export print-ready PDF with the dieline on its own layer — or stage it in a 3D scene for a mockup.