Living Hinge Foldable Envelope – Half Letter Size | PLA/PETG | Stationery Gift | No Supports

Model Overview & Print Notes

## Foldable 3D Printed Envelope with Living Hinges (Source file included, scalable for different paper sizes) A functional, reusable envelope that folds flat like origami using integrated **living hinge** fold lines — no fabric, no tape, no glue. Print it flat, fold it up, slip in your letter. Designed for **half-letter paper (5.5" × 8.5" / 140 × 216mm)** (triple-folded) with clearance on all sides. Built as ONE foldable part under 210 × 200mm so it prints on any standard FDM bed. --- This design uses: - **Filleted groove bottoms** to distribute stress and prevent crack initiation at sharp corners - **Stress relief holes** at every fold-line intersection to eliminate corner tearing - **One-piece tongue-and-groove assembly** ### Inspiration Inspired by living hinge engineering principles applied to FDM printing. Designed from scratch in Fusion 360. Not a remix of any existing model. --- ### Keywords 3D printed envelope, living hinge, flexible envelope, PLA, PETG envelope, foldable 3D print, half letter envelope, stationery 3D print, graduation gift, origami 3D print, functional print, no supports, two-part assembly, snap fit, Fusion 360, flat print ## 3D Printing Settings ## Machine & Material **Machine type:** FDM **Material: PLA/PETG/TPU** — PETG will print best, with the most bend cycles before cracking/breaking. --- ## Slicer Settings | Setting | Value | |---|---| | Layer height | **0.16mm — do not change** | | First layer height | 0.20mm | | Nozzle diameter | 0.4mm | | Infill | **0%** (4 walls fill the 1.4mm panel completely) | | Supports | **None** | Minimum bed size: **220 × 220mm** --- ## Estimated Print Stats - **Time:** ~1 hour per piece - **Material:** ~30g filament per piece --- ## Post-Processing After removing from the print bed, slowly fold each hinge line back and forth to create permanent crease lines and prevent hinge cracking/failure.

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