A tech pack is the document that turns a design into a manufacturable specification: style drawings, measurements, materials, trims, decoration, and packaging all in one place. Sampling fails when the pack is incomplete, because the factory has to guess, and guesses produce samples that miss the mark and consume calendar time. The return on a complete tech pack is faster, more accurate sampling and fewer rounds of corrections. This guide explains what a tech pack must contain, how to write a size chart factories can follow, and the three mistakes that delay sampling most often.
What a Tech Pack Is and Why Sampling Fails Without It
A tech pack is the contract between the brand’s intention and the factory’s production. It does not need to be a professional design document; it needs to be complete enough that a stranger could make the garment from it.
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Who creates the pack matters less than what it contains. A designer, a product developer, or the brand’s own team can draft it; some manufacturers also offer tech pack drafting as part of development. The document is the deliverable, not the tool that made it.
The Core Sections Every Tech Pack Needs
A usable tech pack has six core sections:
- Style page: the front, back, and detail sketches or reference images with a style name and description.
- Measurement table: the graded size measurements with tolerances for each point.
- Bill of materials (BOM): every fabric, trim, label, and packaging item with supplier or specification references.
- Construction details: seam types, stitch density, and finishing instructions.
- Decoration spec: print or embroidery placement, method, colors, and artwork files.
- Packaging and labeling: folding, polybag, carton details, and label content.
Each section answers a question the factory will ask anyway. Putting the answers in the pack removes the back-and-forth.
The bill of materials deserves its own discipline: every component, from the main fabric to the smallest label, should appear with a specification or supplier reference. A missing component on the BOM either gets improvised by the factory or stops production later, and both outcomes are expensive.
Construction details should name the seam type and stitch density for the seams that matter, because a seam specified only as “strong” is open to interpretation. The same applies to finishing: a garment wash, a softener finish, or a pressing standard changes the final product and belongs in the pack.
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Style pages should show the garment from multiple angles with construction callouts, because a single sketch hides the details that matter: pocket placement, seam positions, and finish treatments. Callouts with notes are more useful than beautiful drawings without information.
Writing a Size Chart That Factories Can Follow
The size chart is the most technical part of the tech pack, and it fails in predictable ways.
Name every measurement point with the industry term, from chest and shoulder to sleeve length and body length, and give the value for each size. Add tolerances, because a factory cannot hit one exact number across hundreds of garments; a range such as plus or minus half an inch is a real instruction, while one number is a wish.
State the grading direction clearly: how each measurement changes between sizes. If the grading is left to the factory, its default may not match the fit you intend. A chart with measurements, tolerances, and grading instructions is a chart a factory can follow.
The measurement points themselves should match the product category. A T-shirt needs chest, shoulder, sleeve, and length; underwear needs waist, leg opening, and rise; pants need inseam and hip. Using the wrong points produces a sample that measures “correctly” against the chart but wrong against the product.
Tolerances deserve the same category awareness. Knits stretch and shrink more than wovens, so their tolerances should reflect that behavior; a tolerance designed for woven fabric will reject acceptable knits or accept drifting ones. The tolerance, like the measurement, is a specification, not a default.
The chart should also state the fit profile: slim, regular, or relaxed. The same measurements can produce different fits depending on how the pattern is eased, and naming the profile tells the factory which ease to use.
Specifying Fabrics, Trims, and Decoration
Materials and decoration need the same precision as measurements.
For fabric, name the fiber composition, weight in GSM, and the required performance such as shrinkage or colorfastness. For trims, name the type, width, color, and any quality standard. For decoration, provide the artwork, the method, the placement with measurements, and the size limits.
The rule is that every item the factory must buy or do appears in the pack. A fabric named only as “cotton” leaves the weight and quality open; a print described only as “logo” leaves the size and method open. Both produce surprises at sampling.
Color is another common gap. Naming a color without a reference leaves the shade open; providing a Pantone reference or a physical swatch closes it. The same discipline applies to finishes and washes: state what the fabric should feel like after processing, not just what the yarn is made of.
Three Tech Pack Mistakes That Delay Sampling
1. Incomplete measurements. A chart missing the chest or body length forces the factory to guess the most important numbers. Measure every point you can, and list the points you could not measure as “to be confirmed” rather than leaving them silent.
2. Missing tolerances. Without tolerances, the factory either chases an impossible exact number or chooses its own range. State the acceptable range for the critical measurements.
3. No artwork files. Decoration cannot be executed from a description. Provide vector or high-resolution artwork with dimensions, colors, and placement, or the print sample will be a surprise.
Artwork quality matters as much as its existence. Low-resolution images blur when scaled, missing fonts break the design, and unlabeled color layers get printed wrong. The artwork spec should state the file format, the exact placement measurements, and the color references.
Version control is the silent fourth mistake. When a pack changes between rounds, the factory must know which version is current; a dated filename and a change log prevent the factory from sampling against an old spec.
Send a Complete Brief, Get a Faster Sample
The time invested in the tech pack is returned in sampling speed. A complete pack lets the factory quote accurately, source the right materials, and produce a first sample close to final, which usually means fewer rounds and a shorter timeline.
If you do not have a tech pack, say so: a manufacturer that offers development support can draft one with you, using your references and target measurements. The official workflow of Sino Finetex includes drafting tech packs for brands that lack them, so a rough brief can still become a complete specification.
Digital assets speed the process further: vector logos, reference images in multiple views, and size charts in a standard format. The official workflow lists the branding files it needs, and preparing them alongside the pack shortens the quote and sampling timeline.
A tech pack is not finished when it is written; it is finished when a factory can quote, source, and sample from it without a single clarifying question.
Frequently Asked Questions
What is a tech pack in apparel?
A tech pack is the specification document that describes a garment for production: drawings, measurements, materials, trims, decoration, and packaging.
Do I need a professional designer to create a tech pack?
No. A complete pack needs clear drawings or references and complete measurements, not professional design software. Many factories also offer tech pack drafting as part of development.
What measurements should a tech pack include?
At minimum, the measurements a factory needs to grade and sew the garment: chest, shoulder, sleeve, length, and the category-specific points. Add tolerances and grading instructions.
What is a BOM?
A bill of materials lists every fabric, trim, label, and packaging component with specifications, so the factory can source and cost the order accurately.
How many sample rounds does a good tech pack save?
Typically at least one. A complete pack produces a first sample close to final, while an incomplete pack consumes a round just to discover the missing details.
What files do I need for decoration?
Vector files such as AI, EPS, or SVG, or high-resolution images, with dimensions, colors, and placement. The official workflow also accepts these as artwork files for printing and embroidery.
Can a factory help me create the tech pack?
Yes. Many manufacturers, including Sino Finetex, draft tech packs from reference images and target measurements when the brand does not have one.
