A tech pack is the single document that stands between your idea and the factory floor. When it is bad, you pay for it in sample rounds, phone calls, and delays. When it is good, the factory can work almost independently, and your revisions arrive with fewer surprises.
What must be in it
Every tech pack needs: a cover page (style name, number, season, date, revision number), a flat sketch with callout points, a measurement chart with all relevant dimensions at your base size, a materials list with exact fabric specs (fibre content, GSM, finish), a colourway page (Pantone codes, thread colours, trims), construction notes for each callout point, a bill of materials for fabrics and trims, and label and packaging specifications.
That is the minimum. Factories that work with emerging brands often need more — particularly on the construction notes page. Do not assume the factory knows how you want the hem finished, how deep the pockets should be, or whether the label is woven or printed. Write it down.
What to leave out
Do not put your entire mood board in the tech pack. Do not include photos of inspirational garments with arrows. The factory is not your design partner at this stage — they are executing a specification. Give them specification language: dimensions, tolerances, materials, and construction instructions. Everything else is noise that obscures the signal.
Also leave out measurements that are not relevant to the construction. Spec the finished dimensions, the seam allowances, and the construction method. Let the pattern-maker fill in the geometry.
The unwritten rules
Use the same unit system throughout. Do not mix inches and centimetres. Use consistent terminology — if you call it a raglan seam on the sketch callout, do not call it a set-in sleeve in the construction notes. Number your revisions clearly. When you send a revised tech pack, list what changed at the top. The factory will have printed the previous version. Help them find the differences fast.
Treat the tech pack as a living document until bulk production is approved. Every sample round should generate a set of fit comments that translate into a new revision. The tech pack is your record of the development process — keep it clean, versioned, and complete.