TL;DR: A bag tech pack is a 5–12 page document that contains every detail a factory needs to produce your bag correctly — sketches, materials, measurements, hardware, construction notes, logo placement, and packaging spec. Without a complete tech pack, expect miscommunication, incorrect samples, and expensive revisions. With one, your first sample is typically 85–95% correct.
What Is a Bag Tech Pack and Why Does It Matter?
A tech pack (short for technical package or specification package) is the official communication document between a bag designer or brand and their manufacturing partner. It is the bridge between your creative vision and the physical product that comes off the production line.
Think of it as a construction blueprint for a building. The architect’s sketch is the inspiration; the engineering drawings are the tech pack — precise, measurable, and leave no room for interpretation.
When a factory receives a bag brief without a tech pack, they fill in every gap with their own judgment: they choose the zipper style they have in stock, the interior layout they use most often, the strap length that fits their standard hardware. The result is a bag that might be close to what you imagined — or might be surprisingly different.
When a factory receives a well-constructed tech pack, they have no gaps to fill. They build exactly what is specified. The first sample comes back 85–95% correct, and you are in bulk production within 4–6 weeks instead of 3–4 months of back-and-forth revisions.
The 8 Essential Components of a Bag Tech Pack
Component 1: Cover Page
Simple but important. Should include:
- Your brand name and logo
- Style name and style number (e.g., “Metro Tote — Style MT-001”)
- Colorway reference (e.g., “Colorway A: Black / Gold”)
- Season/collection (e.g., “AW 2026 Collection”)
- Date of document and version number (e.g., “V1, 15 May 2026”)
- Your contact information and your designated factory contact
Version numbers matter. Tech packs evolve through revisions. “V3” tells the factory they should discard “V2” and work from the latest document.
Component 2: Technical Sketches
Technical sketches (also called flat sketches or technical drawings) show the bag from all necessary angles with precise proportions. For most bags, you need:
- Front view
- Back view
- Side view (both sides if asymmetric)
- Interior view (showing all pockets, dividers, and attachment points)
- Detail callouts (close-up annotations of zipper placement, logo position, handle attachment, etc.)
Sketches do not need to be artistic. They need to be accurate. Clean, proportional flat drawings in Adobe Illustrator or even precise hand drawings scanned at high resolution are both acceptable. The factory’s pattern-makers work from these drawings to develop the cutting and construction pattern.
If you are not comfortable with technical drawing, many freelance fashion designers offer tech pack creation services (typically $150–$400 per style) and can work from your reference images or sketches.
Component 3: Bill of Materials (BOM)
The BOM is a complete itemized list of every material and component in the bag. This is the most important section for preventing material substitutions.
A complete BOM includes:
| Component | Description | Specification | Color | Supplier (if specified) | Quantity per bag |
|---|---|---|---|---|---|
| Main body material | Top-grain cowhide leather | 1.0mm, vegetable-tanned | Black (Pantone Black 6C) | [If specified] | ~0.6 sqm |
| Lining material | 210D nylon lining | — | Dark navy | — | ~0.8 sqm |
| Zipper (main) | Metal zip, closed end | YKK #5 metal, antique brass | — | YKK | 1 pc, 35cm |
| Zipper (pocket) | Nylon coil zip | YKK #3 | Black | YKK | 1 pc, 20cm |
| D-rings | Cast zinc alloy | 20mm internal diameter | Antique brass plate | — | 4 pcs |
| Magnetic snap | Magnetic closure | 18mm diameter | Antique brass | — | 1 set |
| Logo plate | Cast zinc logo | Custom shape, 40×15mm | Antique brass | Custom | 1 pc |
| Rivets | Double cap rivet | 8mm cap diameter | Antique brass | — | 8 pcs |
| Thread | Bonded nylon thread | Tex 40 | Black | — | — |
| Hang tag | 300gsm board, 2 sides | 55×90mm with hole | — | — | 1 pc |
| Dust bag | Non-woven, drawstring | 35×40cm | Cream | — | 1 pc |
Every component gets its own row. Nothing is left for the factory to assume.
Component 4: Measurements and Dimensions
All dimensions must be stated in your preferred unit (cm or inches) with tolerance ranges.
For a structured handbag, specify:
- Overall dimensions: L × H × D (e.g., 38 × 28 × 14 cm, ±0.5 cm)
- Handle length (top handles): e.g., “Each handle 32cm in length, 1.5cm wide, with 10cm drop”
- Strap length (shoulder/crossbody): e.g., “Adjustable strap 100–120cm total, 2.5cm wide”
- Interior pocket dimensions: e.g., “Front slip pocket 20 × 15cm, back zip pocket 25 × 15cm”
- Zipper length: e.g., “Main zip 38cm”
- Logo plate position: e.g., “Center front panel, 8cm from top edge”
For leather bags, state that dimensional tolerance is ±5mm (leather stretches and the material does not allow perfect precision).
Component 5: Construction Notes
Construction notes specify how the bag is built — the techniques and sequences the factory must follow. This is the section where the structural integrity of the bag lives.
Key construction notes to include:
- Seam allowance: e.g., “1cm seam allowance throughout”
- Stitch type: e.g., “Lock stitch throughout; saddle stitch on exterior seams” (saddle stitch is more durable on leather)
- Stitch density: e.g., “6 stitches per cm on leather exterior; 7 stitches per cm on lining”
- Edge finishing: e.g., “All leather edges to be burnished and painted with black edge paint, two coats”
- Reinforcement: e.g., “Handle attachment points to be reinforced with 4-rivet bar-tack construction; minimum 6mm rivet cap diameter”
- Base reinforcement: e.g., “Base panel to include 3mm foam interlining for structure”
- Lining attachment: e.g., “Lining attached at zipper tape with 2 rows of stitching”
Component 6: Hardware Details
Hardware (zippers, buckles, D-rings, snaps, clasps) is often where sample quality deviates most from expectation. Be extremely specific.
For each hardware item, specify:
- Type and function (e.g., “20mm D-ring for strap attachment”)
- Material and plating (e.g., “Zinc alloy, 2-micron gold PVD plating”)
- Size (e.g., “Internal opening 20mm × 15mm”)
- Finish (e.g., “Shiny gold / matte gold / brushed gold — specify exactly”)
- Brand if required (e.g., “YKK zipper only — no substitution”)
- Quantity per bag
- Position on bag (refer to technical sketch callout number)
The difference between “antique gold” and “shiny gold” sounds minor but creates a dramatically different look on the finished bag. Always specify.
Component 7: Logo and Branding Specifications
Your logo is the most visible element of brand identity on the bag. Specify it precisely.
Logo specification details:
- Logo file format: provide vector file (AI, EPS, or SVG) — never JPEG for production
- Application method: emboss / deboss / metal plate / screen print / heat transfer / woven label / embroidery — specify which
- Position: exact placement described in measurements from reference points (e.g., “Center front panel, lower edge of logo 8cm from base of bag”)
- Size: exact dimensions in mm (e.g., “Logo plate 45mm × 18mm”)
- Color/finish: e.g., “Antique brass, no lacquer coating”
- Depth (for embossing): e.g., “1.5mm emboss depth on leather”
Component 8: Packaging Specification
Packaging communicates quality before the customer touches the bag. Specify:
- Dust bag: material, size, closure type, color, any printing
- Gift box: size, board thickness, finish (matte/gloss laminate), color, printing
- Tissue paper: color, fold method
- Hang tag: size, paper weight, printing spec (front/back), hole position, cord type and color
- Care card: size, language, content
- Poly bag: size, closure type (zip / header card / self-seal)
- Master carton: bag quantity per carton, carton dimensions, labeling requirements
Common Tech Pack Mistakes and How to Fix Them
Mistake 1: Vague material descriptions (“high-quality leather”) Fix: Specify grade, tanning method, thickness, and finish. “1.0mm top-grain chrome-tanned leather, semi-aniline finish, in color matching Pantone 19-1217 TPX.”
Mistake 2: Missing hardware details Fix: Every piece of hardware gets its own BOM row with material, plating, size, and position.
Mistake 3: No tolerance ranges on dimensions Fix: Add ±5mm for leather, ±3mm for nylon/polyester. Factories need this to manage natural material variation.
Mistake 4: Logo file provided as JPEG Fix: Always provide logos as vector files (AI, EPS, SVG). JPEG cannot scale without quality loss and cannot be used for embossing dies.
Mistake 5: No version control Fix: Date and version-number every tech pack. Factories working from the wrong version is a surprisingly common and costly error.
Do You Need a Tech Pack to Work with a Factory?
Technically, no — many brands work successfully from reference samples and written briefs, particularly for straightforward designs. But if you want a unique design that does not exist in the factory’s library, or if you need to be very precise about any aspect of the product, a tech pack is the most reliable way to ensure you get what you are paying for.
If creating a full tech pack is beyond your current resources, at minimum provide:
- A reference sample (a bag whose construction you want to replicate or reference)
- Written notes on every element you want to change from the reference
- Your logo vector file
- Your material preferences in writing
Largeng Bags can develop a working specification from a reference sample + written brief, producing a first sample that is typically 70–85% correct without a formal tech pack.
📩 Send your tech pack or reference brief to start your first sample → [Contact Largeng Bags at ltbagfactory.com]
