A tech pack is the full technical guide that instructs manufacturers on constructing a garment, detailing every material, measurement, color, and construction element in one document. Manufacturers rely on it for quotes, samples, and quality grading. Yet, despite its importance, many apparel brands still produce the most error-prone section, the measurements, with a tape measure and a spreadsheet.
The core argument is that while the tech pack itself functions well, the process of generating its measurement data is flawed.
What does a tech pack include?
A production-ready clothing tech pack consists of six essential components. Missing any element forces the factory to make assumptions, potentially resulting in wasted sample rounds.
| Component | What it covers | Who reads it hardest |
|---|---|---|
| Technical flats | Front and back line drawings with construction callouts | Pattern maker |
| Bill of materials (BOM) | Every fabric, trim, thread, label, and button, with supplier codes | Sourcing team |
| Measurement spec | Points of measure (POMs) per size, with tolerances | QC inspector |
| Construction details | Stitch types, seam allowances, stitches per inch | Sewing floor |
| Colorways | Pantone codes per color variant, placement notes | Dye house |
| Labeling and packing | Care label content, hang tags, fold and polybag specs | Finishing line |
The measurement spec is the section that often leads to disputes, as it is physically verified. A Pantone code either matches or it doesn't. A specified chest width of 54.5cm with a tolerance of 1cm invites varying interpretations.
Tech pack vs. spec sheet: when to use each
The two documents are often confused since one is part of the other. A spec sheet is solely focused on measurements, while a tech pack covers the entire production process.
| Spec sheet | Tech pack | |
|---|---|---|
| Scope | Measurements and tolerances only | Full production blueprint |
| Length | 1 to 2 pages | 8 to 20 pages |
| When it's enough | Reorders, simple styles, trusted factories | New styles, new factories, anything graded |
| Fails when | Construction is ambiguous | Rarely, if maintained |
For those only needing the measurement details, a companion piece dives into POMs and grading.
How to make a tech pack
Follow these six steps in the sequence factories expect. Completeness is important, irrespective of the tools used. A detailed tech pack in a spreadsheet is preferable to an imprecise one in costly software.
- Draw technical flats, both front and back, with construction callouts.
- Construct the BOM, including every material with a supplier reference and unit cost.
- Draft the measurement spec with POMs per size and tolerances approved by the factory.
- Include construction notes such as stitch types and seam allowances.
- Specify colorways with Pantone references and print or embroidery placements.
- Conclude with labeling, care content, and packing instructions.
Versioning is essential. The tech pack evolves after each sample round, and an unversioned change can lead to two factories producing different garments from "the same" file.
Why do you need a tech pack?
Ambiguity incurs costs through additional sample rounds. Industry estimates suggest a well-constructed tech pack requires 2 to 4 hours of technical design time per style, compared to sampling that costs hundreds of pounds per round. Brands with complete tech packs often reduce sample rounds from four or five to two.
"A factory can only sew what the document says. Every blank cell in a tech pack is a decision you just delegated to someone who has never met your customer."
Beyond cost, there is a quality aspect. The measurement spec becomes the baseline for all subsequent QC checks. An inadequate baseline results in ineffective inspections, which is where many tech packs falter.
The measurement section is where tech packs go wrong
When asked how the numbers in a measurement spec were derived, most brands would admit that a sample garment was measured with a tape, the number was read aloud, and entered into a grid. This process repeats for 15 to 40 POMs per style, size, and sample round.
Three main issues arise.
The numbers drift. Different technicians measuring the same garment may obtain different results. Even the same technician may record varying measurements on different days. The spec ultimately reflects the measurement entered at that moment.
The numbers age. The spec records what the golden sample measured at the time. Production, months later, is checked against a document, not the original sample.
The numbers are thin. A manually created spec might capture around two dozen POMs, but the garment contains far more dimensional information than captured.
This is where measurement capture should integrate with automation. Size AI reads a flat-laid garment in 0.92 seconds, extracting over 400 structured data points with 15+ measurement points per piece at 5 to 9mm typical accuracy, with the best dimensions within 4 to 5mm. The goal isn't replacing technicians with phones, but ensuring the same garment consistently produces the same measurements, essential for a reliable baseline document.
Maintaining honest boundaries is important too. For tech packs with tight tolerances, a tape measure still verifies the final spec. Captured data is valuable for building the spec from a golden sample, keeping QC consistent across stations, and identifying out-of-range pieces before a buyer does.
Standard POMs by garment type
While no two brands share identical POM lists, the core set remains consistent. This should be the minimum standard.
| Garment type | Core POMs | Why they carry the fit |
|---|---|---|
| Tops and tees | Chest width, shoulder width, body length, sleeve length, hem width | Chest and shoulder define the silhouette, while length affects proportions |
| Pants and denim | Waist width, hip width, front rise, inseam, thigh width, leg opening | Rise and thigh impact fit; waist alone can mislead |
| Dresses | Bust, waist, hip, body length, sleeve or strap length | The three-girth chain must grade together or the size run fails |
| Outerwear | Chest, shoulder, body length, sleeve length, sleeve opening | Layering room lives in the chest and sleeve dimensions |
Where automation actually belongs in a tech pack
Automation is not suited for creative sections. Flats, construction logic, and colorway decisions require human judgment, which is apparent to factories when absent. Instead, automation is beneficial in data-driven sections where the task is transcription rather than decision-making:
- Measurement spec. Capture the golden sample digitally once, allowing the POM grid to populate from dimensional garment data instead of dictation. Update similarly after each approved sample round.
- Fiber content and care. The garment's label already specifies composition. Label Scanner reads fiber percentages, care symbols, and origin details with over 95% accuracy. This data can directly inform a BOM line and a care-label spec without manual retyping. We covered the label-as-data-source pattern in the garment label piece.
- The QC baseline. Tolerances in the spec are verifiable during production when inspection measurements are consistently produced. Consistency in, consistency out.
The outcome is a human-created tech pack, with data accuracy no longer dependent on who measures the garment.
What to do next
For those who create tech packs, examine one and verify two aspects: when the measurement spec was last checked against a physical garment, and whether two people measuring that garment would yield the same grid. If either response raises concerns, the solution involves capturing a sample, not acquiring new software.
We work with production and design teams on exactly this: turning sample garments into spec-ready dimensional data per SKU, with an auditable record behind every measurement. Talk to us about what that looks like against your current tech pack workflow.
