Tech pack: the file that makes your style speak factory

A serious tech pack brings together six families of information. Flat sketches, front, back and details, dimensioned and annotated. The finished measurement chart, base size included, with a tolerance for each point of measure. The bill of materials, or BOM: shell fabric, lining, interlining, thread, zips, buttons, labels, each with its reference, composition and supplier when one is imposed. Construction details: seam types, stitches per centimetre, topstitching, interior finishes. Size grading. And finally labelling and packaging: brand label, composition and care labels, folding and packing.

Anything that is not written down will be decided by the factory, according to its habits and its cost price. A missing tolerance becomes the factory’s widest tolerance. An unreferenced trim becomes whatever trim is in stock. An undescribed finish becomes the fastest finish to assemble. None of these decisions is malicious: they are rational for the factory. That is exactly why the tech pack exists. It turns a design intention into instructions the line can follow, and it gives an objective basis to accept or reject a piece.

The same gaps come back from one brand to the next. Measurements taken on the pattern instead of finished measurements. No tolerances, or a single tolerance for the whole garment. Unspecified interlining on a jacket. Trims described with a photo and no reference. Sample comments sent across several messages instead of one numbered list. Each of these usually adds a sampling round, with its delay and its shipping cost. Fixing the file before the first prototype almost always costs less than fixing the piece afterwards.

Some categories need a higher level of detail. In tailoring, the file must state the construction level, fused, half canvas or full canvas, how the shoulder holds, the lapel roll and how the interior is finished. In outerwear, it must describe seam sealing, the fill type and its weight by zone, any lamination, and zips suited to cold weather. These are exactly the points where a generalist factory improvises, and where a premium brand wins or loses.

There are three options. The brand’s studio writes it in house, which assumes a pattern maker or a product developer. The factory completes it from sketches, but then writes it to its own standards. Or a production office creates or corrects it, checking it against what the line can actually do. At Lebrun Production, creating or correcting a tech pack costs 150 to 300 euros per style, depending on complexity. The file belongs to you and remains usable with any factory.

A tech pack is not a frozen document. It is the basis for the first prototype, then it grows with every sample comment until the approved version goes into production. Each deviation is tied to the point of measure or the BOM line concerned, which makes corrections traceable. That final version is the reference for the pre-shipment inspection: a piece that matches the tech pack is accepted, a piece that departs from it is discussed on evidence, not on impressions.

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• 01 Clothing sample maker: who does it, what you pay
• 02 First production in Asia: the pack
• 03 Tailoring production in Vietnam
• 04 The menswear production office