Why does my mailer box bulge at the sides if I don't set board thickness (T)?

In a FEFCO 0427 mailer box, the side walls fold 180 degrees over the internal dust flaps. If the rollover bridge equals zero instead of 2T + 0.5mm, the outer wall crushes the inner dust flap and forces the side panels to bow outward.

Are the dimensions entered in this FEFCO 0427 generator Inside Dimensions (ID) or Outside Dimensions (OD)?

All dimensions (L x W x H) entered into CadFold packaging generators represent strict Inside Dimensions (ID)—the usable internal cavity available for your product. Outer dimensions are automatically expanded by the board thickness formula.

How do I open the exported SVG or PDF in Adobe Illustrator at exact 1:1 millimeter scale?

Our SVG and PDF files embed explicit physical millimeter units (mm) in the root header rather than screen pixels. Simply use File > Open in Adobe Illustrator (do not drag-and-drop onto a scaled artboard) and verify the 50mm calibration scale bar at the bottom.

Can I cut an E-flute corrugated mailer box prototype on a CO2 or Diode laser cutter?

Yes. Export the .DXF or .SVG file with 'Include Dimensions Layer' unchecked. Assign the RED (CUT) layer to 100% through-cut power (e.g., 45mm/s at 35% power on a 60W CO2 laser) and the BLUE (CREASE) layer to a light surface score or dashed perforation (120mm/s at 12% power).

TEMPLATE ID: PRE-PKG-004 152 × 102 × 51 mm (T=1.5mm) Pre-Verified 1:1 Static Files Ready

6x4x2 Inch (152 x 102 x 51 mm) E-Commerce Mailer Box Dieline Template

Interactive Parametric 2D & 3D Studio

Live 2D Dieline, Interactive 3D Fold Preview & Custom Size Generator

Pre-loaded with 6x4x2" Small Mailer Box (152×102×51 mm, T=1.5mm)

1:1 CAD ENGINE READY

6x4x2 Inch (152 x 102 x 51 mm) E-Commerce Mailer Box Dieline Template

1CAD Style & Material SetupPackaging

Select CAD Style / Model (36)Search & Filter

Material Stock Preset (Auto-Sets Caliper T & Kerf K)

Display Units

Reference Mode

2Dimensions (ID Mode)Millimeters (mm)

Internal Length (L)152 mm

Internal Width (W)102 mm

Internal Height / Flange (H)51 mm

Inside ID: 152×102×51mmOutside OD: 155×105×54mm

Thickness (T mm)

Laser Kerf (K mm)

3Brand Logo & 1:1 ExportZero Login

2D & 3D Brand Logo Mockup:

📤 Upload Logo

Print Artwork Bleed Guide:

Embed Spec Sheet & 50mm / 1" Scale Bars (Added on separate DIMENSIONS layer)

Pre-Flight Geometry Audit8/8 PASSED

PASS
Closed Outer Contours: 3 closed LWPOLYLINE cut loop(s) verified
PASS
Zero Duplicate Cut Paths: 42 unique segments (0 laser double-burns)
PASS
Flute & Kerf Tolerance Guard: T=1.50mm, K=0.000mm within structural limits
PASS
ISO Layer Color Separation: CUT (Red), CREASE (Blue), SCORE (Emerald), DIMENSIONS isolated
PASS
1:1 Physical Unit Header: Explicit mm/in SVG viewBox + DXF $INSUNITS=4 + 50mm PDF bar
PASS
Exact 2D Cut Bounding Parity: Cut Bounds 358.5×339.15mm === Blank Size
PASS
2D ↔ 3D Kinematic Model Sync: Archetype 'mailer_0427' synced (6 3D component(s))
PASS
True Vector Sheet Nesting Sync: 1:1 vector paths mapped to multi-up sheet grid

100%

CUT (2.07m) CREASE/SCORE (1.66m)● 3 Loops · Est. Cut: ~70s

1:1 Synced · Blank: 358.5 × 339.15 mm

2D 1:1 Unfolded Vector BlueprintBlank: 358.5 × 339.15 mm (14.11" × 13.35")

3D Interactive Fold & Orbit (Kraft Board)

80%

0%100%

Camera:

Yaw: -28°Pitch: 24°

⟳ Drag Anywhere to Rotate 3DL=152 × W=102 × H=51mm

BASE (152×102mm)

FRONT (H=51)

REAR WALL

TOP LID (80%)

TUCK FLAP + EAR LOCKS

Flat Blank Size

358.5 × 339.1 mm

Rollover Bridge (2T)

3.50 mm

Sheet Area

0.122 m²

FEFCO Standard

FEFCO 0427 (RETT)

Direct Pre-Generated 1:1 CAD Files

Download Static Ready-to-Cut Files (152×102×51 mm)

These static files are pre-calculated for 1.5mm material thickness. Click any format below to download the pre-built static file, or export custom dimensions directly from the interactive Studio above.

↓ Download .DXF AutoCAD / LightBurn ($INSUNITS=4) ↓ Download .SVG Illustrator / Corel (1:1 mm) ↓ Download .PDF 1:1 Print + 50mm Scale Bar

Product Manufacturing Specification Sheet

Calibrated Physical Clearances & Material Stock for 6x4x2" Small Mailer Box

Parent Parametric Engine: FEFCO 0427 Mailer Box →

Target Physical Product Size

152.4 mm x 101.6 mm x 50.8 mm (6" x 4" x 2" USPS First-Class / Royal Mail Small Parcel Tier)

Engineered Internal Cavity & Clearance

Exact 1.5mm E-Flute double-wall rollover bridges (3.5mm bridge width)

Recommended Board / Sheet Stock

32 ECT E-Flute Corrugated Kraft or White-Top Linerboard (1.5mm thickness)

Grain / Flute Orientation Rule

Flute Corrugations Parallel to the 51mm Height axis for maximum top-to-bottom stacking crush resistance

Production Engineering Note: The 6x4x2 inch mailer is the #1 most popular small parcel size on Shopify and Etsy for jewelry, phone cases, cosmetics, and tech accessories.

Structural Geometry & Material Reference (FEFCO 0427 / Die-Cut Roll-End Tuck Top (RETT))

The FEFCO 0427 (Roll-End Tuck Top / RETT) mailer box is the global industry standard self-locking corrugated packaging design for e-commerce subscriptions, retail kits, and D2C shipping. Engineered from a single die-cut sheet without glue or tape, it features double-layered side walls that fold over integrated dust flaps and lock into precision bottom slots, while the hinged top lid secures via dual front friction-lock ears. Our parametric engine automatically compensates for corrugated board thickness (T) across E-flute (1.5mm) and B-flute (3.0mm) by widening rollover bridges by 2T and setting dust flaps back by 1.5T to prevent fiber crushing.

Total Flat Blank Width (W_blank)

W_blank = L + 2(H) + 2(2T + H_rollover) + 2(W_lock_ear)

Accounts for interior length (L), two vertical side walls (H), two double-wall rollover bridges (2T), and two inner locking wall panels.

Total Flat Blank Length (L_blank)

L_blank = H_back + W_base + H_front + W_lid + H_tuck_flap + 3.5T

Sums the rear wall, bottom base, front double wall, top lid panel, front tuck-in flap, and cumulative 90-degree flute crease allowances.

Rollover Bridge Allowance (Delta_bridge)

Delta_bridge = 2 * T + 0.5 mm

Essential double-crease spacing that wraps over both the vertical side wall and the tucked dust flap without buckling.

Internal CAD Silo & Related Ready-to-Cut Templates