A tech pack is the single document that carries everything a manufacturer needs to cut, sew, and finish your garment correctly. Get it right and your first proto comes back close; leave a section out and you get a call, a delay, or a sample that misses the mark entirely. This guide walks through every mandatory section in the order factories expect to see them.
Key takeaways
- A production-grade tech pack has seven non-negotiable sections; omitting any one of them forces the factory to guess.
- The BOM is where most costing errors originate — every component, colorway variant, and placement must be itemised before sampling begins.
- A revision log is not optional paperwork; it is the audit trail that protects you when a factory claims it never received an update.
- Graded measurements belong in the tech pack itself, not in a separate file sent later.
- Digital tools can enforce completeness, but the technical designer still owns the content.
What is a tech pack and why does every section matter?
A tech pack — short for technical package — is an industry-standard specification document that travels from your design team to your manufacturer. Techpacker's guide to tech packs describes them as the complete reference a factory uses to build a garment without needing to ask follow-up questions. As students at NC State's Wilson College of Textiles put it when completing industry-standard spec packages: "Every tech pack includes detailed measurements for each size, trims, finishes, yarn types and anything else that a manufacturer needs to know when producing the garment."
The consequence of an incomplete tech pack is not just a bad sample. It is rework time, air-freight costs to get a corrected proto back, and — at worst — a bulk run built to the wrong spec. Each section below exists because factories need that specific information at a specific stage of production.
Section 1: Cover page
The cover page is your garment's identity card. It must include:
- Style name and style number — the unique identifier that links every document, label, and purchase order to this exact garment
- Season and year
- Brand name and division (if applicable)
- Colorways with colour codes (Pantone or brand-specific)
- Fabric category (woven, knit, denim, etc.)
- Target gender and size range
- Revision number and date of the current version
- Technical designer and merchandiser contact details
When a factory receives a shipment of tech packs for a season, the cover page is how they sort and file them. A missing style number means your garment gets confused with another. A missing revision number means nobody knows which version is current.
Section 2: Flat sketch (technical drawing)
The flat sketch is a front and back technical illustration of the garment drawn to proportion, without a figure. It shows:
- All seams and stitch lines — including topstitching, bartacks, and edge finishes
- Hardware and trim placement — zipper pull position, button spacing, pocket placement
- Detail callouts — arrows pointing to specific construction features with written notes
- A close-up detail view for any complex area (collar stand, cuff attachment, waistband construction)
The flat sketch is not a mood board image or a fashion illustration. It is a technical drawing. If your factory's pattern maker cannot read a construction detail from the sketch, add a callout. When in doubt, add more callouts.
Section 3: Bill of Materials (BOM)
The BOM lists every physical component that goes into the garment. According to 383 Design Studio, the BOM is crucial because it lists all materials and helps get accurate costing. A complete BOM row includes:
- Component name (e.g., "Main shell fabric", "Lining", "Zipper", "Care label")
- Supplier name or code
- Material composition (e.g., 100% recycled polyester, 420D)
- Colour and colour code
- Width or unit of measure
- Estimated consumption per garment
- Placement (e.g., "CF zipper, from neck to hem")
- Unit cost (if costing is included in the tech pack)
Colorway variants — where the same component comes in different colours for different SKUs — must each have their own row. Fashion Index's BOM guide covers placement and cost breakdown in detail. The BOM is where most costing errors originate. If a trim is missing from the BOM, the factory either sources it independently (at unknown cost and quality) or stops and asks.
Section 4: Measurement chart (size spec)
The measurement chart defines the garment's dimensions at every point of measure (POM) for the base size. It must include:
- Point of measure labels — numbered and consistent with the flat sketch callouts
- How-to-measure instructions — where to place the tape, whether to measure flat or doubled
- Tolerance — the acceptable deviation above and below each measurement (e.g., ±0.5 cm)
- Base size measurements in the unit your factory works in (cm or inches — pick one and stick to it)
Do not send a measurement chart without tolerances. A factory that receives no tolerance guidance will apply its own, and those may not match your fit standards.
Section 5: Construction and stitching details
This section translates the flat sketch into process instructions. It tells the sewing room exactly how to build the garment:
- Stitch type for each seam (e.g., 301 lockstitch, 504 overlock, 401 chainstitch)
- Stitch density (stitches per centimetre or inch)
- Seam allowance at each seam
- Seam finish (serged, bound, flat-felled, French seam)
- Pressing instructions for each panel
- Thread colour and type per seam
- Special processes — bonding, welding, taping, embroidery placement with registration marks
If your garment has a complex construction — a multi-panel hood, a set-in sleeve with a specific ease, a welt pocket — include a step-by-step construction sequence for that detail. Do not assume the factory has built this style before.
Section 6: Graded measurement chart
The graded chart extends the base-size measurements across the full size run. Every size in your range needs its own column, with the grade increment shown between each size so the pattern maker can check the math.
Grading belongs in the tech pack — not in a separate file sent after sampling. Factories use the graded spec to cut the first proto in the base size and to prepare the size set for fit approval. If the graded chart arrives late, the size set is late.
For each size, include:
- All the same POMs as the base-size chart
- The grade increment (positive or negative) between adjacent sizes
- Tolerances (these may differ by size at the extremes of the range)
Backbone PLM's tech pack workflow — now operated under Bamboo Rose — describes importing an existing spec via CSV or building POMs manually, which reflects the two most common approaches teams use in practice.
Section 7: Revision log
Every change to a tech pack must be recorded. The revision log is a table at the end of the document (or on the cover page) that shows:
- Revision number (Rev 01, Rev 02, etc.)
- Date of change
- Description of what changed (e.g., "Updated chest measurement from 52 cm to 54 cm", "Changed zipper supplier from YKK #5 to YKK #3")
- Name of the person who made the change
Without a revision log, a factory working from an older version has no way to know the document has been updated. Backbone's revision management guide notes that the feedback and revision section is the primary reference point for quickly comparing changes made at each development stage — covering updated images, graded size specs, proto sample measurements, and BOM changes.
Keep the revision log even if you are working in a PLM system that tracks versions automatically. The exported PDF that travels to the factory must be self-contained.
How do digital tools help you build complete tech packs?
Spreadsheets and Illustrator files can hold all seven sections, but they make it easy to miss something and hard to collaborate across time zones. Purpose-built tools enforce structure.
Techpacker offers a standalone tech pack editor for solo designers and indie brands, as well as a PLM platform for scaling teams that need to connect product data, teams, and manufacturers in one place.
BeProduct is a SaaS PLM and digital product creation platform with tech pack management, material and colour libraries, sample tracking, and real-time collaboration — positioned for emerging brands that need to centralise product data without enterprise-scale complexity.
Backbone PLM, now part of Bamboo Rose, provides PLM tooling for product development workflows including tech packs, approvals, and supplier collaboration, targeting retailers managing private-label at scale.
Centric PLM, part of Dassault Systèmes, ships an AI-powered PLM platform covering the full product lifecycle across fashion, cosmetics, and retail, with complementary tools for planning, pricing, visual boards, and product experience management.
Whichever tool you use, the underlying discipline is the same: every section must be present, every field must be filled, and every revision must be logged before the document leaves your desk.
What goes wrong when sections are missing?
Here are the most common omissions and their downstream effects:
| Missing section | What the factory does | Cost to you |
|---|---|---|
| Cover page style number | Files the tech pack under the wrong style | Wrong garment gets sampled |
| BOM trim row | Sources a substitute trim independently | Unexpected cost, wrong look |
| Tolerances on measurement chart | Applies its own tolerances | Proto fails fit approval |
| Graded chart | Waits for the file or grades manually | Size set delayed |
| Construction stitch type | Uses its default stitch | Wrong seam appearance or durability |
| Revision log | Works from an outdated version | Bulk run built to wrong spec |
The pattern repeats: a missing section is not a minor gap. It is a decision the factory makes for you.
FAQ
What is the difference between a tech pack and a spec sheet? A spec sheet typically refers to the measurement chart alone — the points of measure and their values. A tech pack contains the spec sheet plus the flat sketch, BOM, construction details, grading, and revision log. The terms are sometimes used interchangeably, but a spec sheet on its own is not enough to send to a factory.
How many pages should a tech pack be? There is no fixed page count. A simple T-shirt tech pack might run four to six pages; a technical outerwear piece with multiple panels, hardware, and bonded seams can run fifteen or more. Length should follow complexity, not a template.
When should I send the tech pack to the factory? Send a complete draft — all seven sections — before sampling begins. Do not send a partial pack with the intention of filling in the BOM later. Factories schedule sampling based on what they receive; an incomplete pack delays the start or produces a sample built on assumptions.
What unit of measurement should I use? Choose centimetres or inches based on what your factory uses, and state the unit clearly on the measurement chart. Mixing units within a single document is a common source of costly errors.
How do I handle multiple colorways in one tech pack? Keep one tech pack per style, not per colorway. Use the BOM to list each colorway variant as a separate row for any component that changes colour. The cover page should list all colorways with their codes.
Further reading
- What Is a Tech Pack? — Techpacker
- Tech Pack BOM Guide — Fashion Index
- What is the BOM for a Fashion Tech Pack? — 383 Design Studio
- The Ultimate Guide to Tech Packs — White Label Manufacturing