What a tech pack is for
A factory is not guessing at your product because it is careless. It is guessing because a picture of a jacket does not say how long the sleeve is, what the lining is made of, how far the pocket sits from the centre front, or whether the zip is a #3 or a #5. Somebody has to decide all of that. The only question is whether it is you, in a document, before production — or a machinist in another timezone, at 2am, on the day of the cut.
That is the whole function of a tech pack. It moves every open decision from the factory floor back to the desk, where changing it is free.
It does a second job that only becomes obvious the first time something goes wrong. When the sample arrives 3cm too short in the body, the tech pack is what makes that a fault rather than a disagreement. Without an agreed spec there is no standard to have fallen short of, and the conversation becomes a negotiation about what you meant — one you will usually lose, because the factory has already bought the fabric.
What goes in a tech pack
The sections below are close to universal for sewn goods. Names vary between brands and between regions; the content does not.
| Section | What it carries | What goes wrong without it |
|---|---|---|
| Cover / summary | Style name and number, season, category, size range, revision number and date. | Two versions of the pack in circulation and no way to tell which one the factory cut from. |
| Technical flat | A drawn, proportional, front-and-back line drawing — no shading, no model, no styling. | The factory works from a mood photo and interprets the silhouette. |
| Points of measure | Every measurement, where to take it from, its value at each size, and a tolerance. | A garment that fits nobody, and no basis to reject it. |
| Bill of materials | Every component bought separately: shell, lining, thread, interfacing, trims, zips, labels, packaging. | Substitutions made on price without anyone being asked. |
| Construction callouts | Seam types, stitch class and density, edge finishes, topstitch distances, reinforcement points. | A product that looks right and fails at the third wash. |
| Colourways | Each colour version, with a reference standard per component rather than a screen colour. | Trim that does not match the shell, on every unit. |
| Labels & branding | Main label, care label, size label, hangtag — artwork, placement, dimensions, attachment. | A neck label sewn in upside down across a whole run. |
| Packaging | Fold method, polybag size, barcode placement, carton pack ratios. | Goods that arrive creased, or that a retailer refuses at the door. |
| Compliance & safety | Required testing, fibre content and country-of-origin copy, age grading and warnings where the category needs them. | A shipment held at customs, or a product that cannot legally be sold. |
Not every product needs every section, and a first sample often runs on a subset. But each one you skip is a decision you have handed to someone who has never met your customer.
An example page
The points-of-measure table is the section people picture when they picture a tech pack, and the one most often done badly. It is not a list of measurements. It is a list of measurements with a stated method and a stated tolerance, graded across every size you intend to sell.
| Code | Point of measure | How to measure | S | M | L | Tol. |
|---|---|---|---|---|---|---|
| A | Chest, 1" below armhole | Across, doubled | 19 | 20½ | 22 | ± ½ |
| B | Body length from HPS | High point shoulder to hem | 27 | 28 | 29 | ± ½ |
| C | Shoulder to shoulder | Seam to seam across back | 17 | 18 | 19 | ± ¼ |
| D | Sleeve length | Shoulder seam to cuff edge | 8 | 8½ | 9 | ± ¼ |
| E | Neck width | Seam to seam, inside edge | 7 | 7¼ | 7½ | ± ⅛ |
Three things about that table are doing the real work. The method column, because "chest: 20½" means nothing until everyone agrees where the chest is measured and whether the figure is flat or circumference. The tolerance column, because no factory hits a number exactly and a spec without a tolerance is either meaningless or unmeetable. And the grading — the change from size to size — because grading is not one number applied everywhere: a neck grows far less between sizes than a chest does, and a pack that grades everything by the same increment produces a size XXL with a collar you cannot get your head through.
A rule of thumb on length. A simple tee runs about 8–15 points of measure. A tailored jacket can pass 30. If your table has four rows, it is not that your product is simple — it is that the factory is about to decide the other twenty.
Tech pack vs. spec sheet vs. bill of materials vs. pattern
These four get used interchangeably and are not interchangeable. The distinction matters most when a factory asks for one of them and you send another.
| Document | What it is | Relationship |
|---|---|---|
| Tech pack | The complete build document for one style. | Contains the spec sheet and the BOM. |
| Spec sheet | The measurement table alone — points of measure, sizes, tolerances. | One section of a tech pack. Often sent alone by mistake. |
| Bill of materials | The purchasing list: every component, supplier, colour, consumption per unit. | Another section of a tech pack. Drives costing. |
| Pattern | The actual cutting shapes, digital or paper. | Produced from the tech pack, usually by the factory. Not part of it. |
The short version: every tech pack contains a spec sheet, and a spec sheet on its own is not a tech pack. If a factory says "send me the tech pack" and you send a measurement table, you have answered about a fifth of the question.
Who writes one
At a large brand, a technical designer or product developer — a specialist role that exists because the document is genuinely skilled work. At a small one, the founder, usually working from a template downloaded once and reused ever since.
A third pattern is common and worth naming: the factory writes it for you. That is not free help. A pack written by the factory records what the factory intends to make, which is not always what you intended to buy, and you are approving a document written by the party it is meant to hold to account. It is workable for a first sample. It is a poor basis for a second supplier quote, because you have nothing portable to send them.
What happens without one
The failure is rarely dramatic. It is a sleeve an inch long, a lining in the wrong weight, a label sewn at the wrong depth — each individually small, each individually arguable, and collectively a run you cannot sell at the price you costed.
- You cannot compare quotes. Two factories pricing from two different understandings are not quoting the same product, and the cheaper number usually just describes a cheaper interpretation.
- You cannot reject a sample. Nothing is wrong if nothing was specified.
- You cannot reorder. Six months later, nobody — including the factory — remembers which thread, which interfacing, which placement.
- You cannot change supplier. The specification lives in one factory's institutional memory, which means so does your product.
How detailed it has to be
The honest test is not "is this thorough" but: could a competent factory that has never spoken to me build this and get it right? Every question they would have to email you about is a gap.
Two failure modes, and the second is less obvious. Under-specifying hands decisions away. But over-specifying — dictating a seam allowance the factory's machines cannot hold, or a construction that is wrong for the equipment on their floor — does its own damage, because it either gets silently ignored or drives the price up for no benefit. Specify the outcome you need and the tolerance you will accept. Leave the factory the methods it is better at than you are.
Outside apparel
Tech packs are talked about as a fashion document because that is the industry that named them, but anything manufactured to a specification uses the same artefact. The structure holds and the sections change:
- Plush and soft toys — fill weight and type, fabric pile direction, safety-eye attachment and pull-test requirements, embroidery versus print for facial features.
- Pet products — chew and tear resistance, stitching reinforcement, weight ratings, filling certification.
- Headwear — crown panel count, buckram, sweatband spec, closure type, embroidery stitch count.
- Bags and accessories — hardware finish and plating, webbing weight, edge painting, load bearing points.
- Hardgoods — materials and finishes, tooling notes, assembly sequence, dimensional drawings.
What stays constant across all of them is the reason the document exists: somebody who has never seen the product in your head has to build it anyway. The category-by-category guide covers what each one adds and what it drops.
Common questions
What does a tech pack mean in fashion?
The document a brand hands its manufacturer to have a garment made — flats, graded measurements, bill of materials, construction callouts, colourways and labelling. The factory quotes from it, cuts from it, and is measured against it when the sample comes back.
Is a tech pack the same as a spec sheet?
No. A spec sheet is usually just the measurement table. A tech pack contains it along with everything else the factory needs. Every tech pack contains a spec sheet; a spec sheet on its own is not a tech pack.
Do I need a tech pack to get a sample made?
In practice, yes. A factory can sew from a sketch, but every decision the sketch does not make gets made by whoever is at the machine — and there is no agreed document to compare the sample against, so nothing that comes back can be called wrong.
Who writes the tech pack?
At a large brand, the technical designer or product developer. At a small one, usually the founder — and sometimes the factory writes it back to them for approval. The document matters more than the job title on it.
Are tech packs only for clothing?
No. Plush, pet, headwear, accessories and hardgoods all use the same document under one name or another. The sections change with the category; the reason it exists does not.