Module 2: Build the Tech Pack
The tech pack is the document factories actually build from — materials, measurements, construction, artwork, packaging, and the quality limits that define a defect. This module builds one page by page, using a grip sock as the worked example.
What a tech pack is — and what happens without one
A tech pack (technical package) is the complete written specification of your product: everything a factory needs to make it exactly the same way twice, and everything you need to prove a mistake when one happens. Pattern-makers call it the product's recipe and blueprint in one document. Factories call it the file they quote from, sample from, and — when a dispute comes — the file that decides who pays.
Without one, every conversation is interpretive. You said “soft cotton sock”; the factory heard its cheapest cotton blend. You pictured a grip covering the whole sole; production printed it on the heel only, because that is how their stock sock is made. Neither party lied. There was simply no document senior to anyone's memory, so the product became whatever the production line already knew how to do.
A tech pack also makes quotes honest. Send five factories the same pack and the price spread tells you something real about their efficiency and margin. Send five factories a photo and the spread tells you nothing — you are comparing five different products that happen to share a photograph. Sourcing, the next module, is only as good as the document it circulates.
One more function, the one founders appreciate latest: the tech pack is your quality contract. When the pre-production sample is approved, it is approved against the pack. When bulk arrives wrong, the pack — plus the approved sample — is the evidence that gets a remake or a credit instead of an apology. Write it like someone who expects to need it, because at volume, everyone does.
The document a factory quotes, samples, and builds from — the product's complete written specification — is called a .
Bulk production arrives with the logo printed 2 cm lower than your sample. You have no tech pack. Where do you stand?
Page by page: the complete tech pack
A working tech pack for a soft good runs six to ten pages. Build it in a spreadsheet or a document — format matters less than completeness. Here is the page order factories expect, with the grip sock as the running example.
Page 1 — Overview. Product name, style number, season, a clean front/back photo or sketch, and the revision date. Every later page carries the same style number and date; factories work from printed pages, and an undated page is a future argument. Page 2 — Bill of materials (BOM). Every material with its exact spec: “body: 75% combed cotton / 20% nylon / 5% spandex, 200-needle knit”, “grip: silicone, Pantone-matched, full-sole pattern per artwork page”, thread, elastic, labels, packaging — each with supplier or spec, color, and placement.
Page 3 — Measurements. A size chart with a measurement for every dimension that matters, per size, each with a tolerance (next lesson). For the sock: foot length, leg height, cuff width, arch band width — measured flat, in centimetres, with the measuring method noted. Page 4 — Construction. How it is put together: seam types, stitch counts, where elastic sits, toe closure method (seamless hand-linked vs. machine seam is a comfort difference customers feel), reinforcement zones.
Page 5 — Artwork & print. Each graphic at full size, colors called out by Pantone or thread number, placement measured from fixed points (“logo center 30 mm below cuff edge”), and repeat/tiling rules. Page 6 — Packaging & labels. The belly band or box with dieline dimensions, barcode placement, care and content labels with the exact legal wording for your market, polybag spec if used, and how pairs are folded. Final page — revision log: date, page, what changed. Factories price and sample from the latest revision; the log is how you prove what “latest” was.
Where does “silicone grip, full-sole pattern, color-matched to the body yarn” belong in the tech pack?
Materials, measurements, and tolerances
Factories do not build to intentions; they build to numbers with tolerances — the plus-or-minus range inside which a unit is correct. A measurement without a tolerance is a wish. “Leg height 12 cm ± 0.5 cm” is a spec: a sock at 11.4 cm is a defect you can reject, and a sock at 11.7 cm is one you must accept. Writing tolerances forces the honest question early: how exact does this dimension actually need to be, and what are you willing to pay for exactness?
Materials deserve the same precision. “Cotton” is a category, not a spec. Combed cotton at 75% with nylon for durability and spandex for recovery behaves nothing like a 40% cotton blend — in feel, in wash life, in cost. Spec the fiber percentages, the yarn or fabric weight, the knit or weave, and the finish. Where you genuinely do not know the right spec, say what the material must do — “grip must survive 50 home washes without peeling” — and let sampling prove which spec achieves it. Performance specs you then test are legitimate; vague material names are not.
Grade your sizes from one measured base. Build the size chart by measuring a reference product you love, size by size, then adjusting: our sock's M/L foot length came from measuring three best-selling pairs and splitting the differences that caused returns. Never copy a size chart from a listing — you inherit their grading errors along with their numbers.
Finally, mark the two or three specs that are critical — the ones that carry the promise. On the sock: grip coverage, grip wash life, cuff hold. Critical specs get the tightest tolerances, the explicit tests in Module 4, and a bold line in the pack. When production pressure comes — and it comes — everyone knows which specs may never be quietly traded away.
Your turn: Write your product's spec sheet draft: every material with percentages/weight, every key measurement with a tolerance, and mark the 2–3 critical specs with a star.
Saved.
A tech pack lists “cuff width: 8 cm” with no tolerance. Production delivers cuffs between 7.2 and 8.9 cm. What happens?
Artwork, packaging, and labels
Artwork fails in production for boring reasons: files at screen resolution, colors named “peachy pink”, placement described as “near the top”. Prevent all three. Send vector files (or print-resolution at actual size), call every color by Pantone for print and thread number for embroidery, and measure every placement from a fixed physical point. A factory in another time zone should be able to place your logo at 3 a.m. with no questions — that is the standard the page is written to.
Packaging is part of the product, priced in the BOM and specced like anything else. Decide the format by how the product is sold and shipped: a belly band for a pair of socks costs a fraction of a box, shows the product, and survives a mailer; a rigid box earns its cost in gift sets and retail shelves, and bankrupts a $20 single pair. Spec dimensions, board weight, finish, and the fold — and always spec what the customer touches first, because unboxing order is a design decision too.
Labels carry law, not just branding. Fiber content and country of origin on apparel, care instructions, your business name and address or a registered identification number where your market requires it, barcode for retail. The exact wording differs by country and product category — check your market's current rules and write the label text into the tech pack verbatim, so the factory prints your words, not a template's.
One discipline covers this whole lesson: approve print from physical proofs. A strike-off (a printed sample of your artwork on the real material) or a pre-production sample in final packaging is the only color-accurate approval there is. Screens lie politely; a proof on the actual fabric, next to your Pantone chip, does not.
Your artwork file says the grip should be “a soft peach color, placed on the sole”. What will production most likely deliver?