How to write a tech pack a factory can actually follow

What a tech pack is for

A tech pack is a set of pages that tells a factory exactly how to make one style. It covers what the garment looks like, what it is made from, how big it is in every size, how it is sewn, and how it is labelled and packed.

It does three jobs at once:

• It lets a factory quote properly. Without fabric, trims and construction details, a costing is a guess.
• It lets a pattern maker build the first sample. The closer the first sample is, the fewer rounds you need.
• It becomes the reference for quality checks. Finished goods are measured and inspected against the tech pack and the approved sample. If something is not written down, it is hard to reject.

You do not need expensive software. A clear PDF or spreadsheet works. What matters is that every question a pattern maker or line supervisor might ask is already answered on the page.

The sections every tech pack needs

Most tech packs follow the same order. Leave a section out and someone in the factory will fill the gap with their own assumption.

1. Cover page. Style name and number, season, category, size range, fit (Indian, international or both), fabric summary, date and version number.
2. Flat sketches. Front and back technical drawings in clean lines, not fashion illustrations. Add close-up callouts for pockets, plackets, collars, cuffs and any detail that is hard to see at full scale.
3. Spec sheet. The points of measure (POM) for your base size, how each is measured and the tolerance allowed.
4. Grading. How each measurement changes from size to size.
5. Bill of materials (BOM). Every material that goes into the garment: shell fabric, lining, interlining, thread, buttons, zips, elastic, drawcords, eyelets, labels, tags and packaging. Give composition, weight (GSM for knits, GSM or ounces for woven and denim), width, colour reference and supplier code if you have one.
6. Construction details. Seam types, stitch types, stitches per inch, seam allowances, topstitch placement, hem finishes, and which seams are overlocked, flat-locked or bound.
7. Colourways. Each colour version and what changes: shell, contrast panels, thread, trims. Use a recognised colour reference or send a physical swatch.
8. Artwork and placement. Prints, embroidery and appliqué with file, size, colours and placement measured from a fixed point such as the high point shoulder or centre front.
9. Labels and packaging. Main label, size label, care and composition label, hang tag, barcode or price sticker, and where each one goes. Then folding method, polybag, pieces per carton and carton marking.

The BOM and construction pages deserve extra care. Together they drive both cost and quality. Two shirts that look the same in a photo can cost very differently because of fabric weight, button quality, seam type or the number of operations.

For each BOM line, include:

• Item and where it is used
• Composition and weight or size
• Colour reference
• Quantity per garment (for example, 7 buttons, 1 zip of 18 cm)
• Supplier or reference code, if you have a preference

For construction, write in plain terms: "Side seams: 4-thread overlock. Hem: 2 cm double-turned, single needle." Close-up photos of a garment you like, with arrows, help a great deal. So does a note on what matters most to you, such as "clean inside finish is important, garment is often worn open".

Points of measure and tolerances

The spec sheet is where most confusion starts. Each point of measure needs a name, a clear description of where the tape goes, the measurement in your base size and a tolerance.

Here is a simple example for a women's woven shirt in size M. The numbers are illustrative only.

A few habits make a spec sheet far easier to follow:

• Say whether a measurement is flat or circumference. "Chest 52" could mean half chest or full chest. Write "edge to edge, x2" or "half measure" so nobody guesses.
• Tighten tolerances where fit depends on them. Shoulders, neck and cuffs need tight tolerances. Long body measurements can be looser.
• Use one unit. Centimetres or inches, not a mix.
• Add a measuring diagram. A simple flat with lettered arrows matching the codes in your table removes most questions.

Grading: getting every size right

Grading sets how much each measurement grows or shrinks between sizes. You can show it as a full table of every size or as increments from the base size (for example, chest +4 cm per size up).

Things to decide before you send it:

• Your size range and size names. S to XL, 28 to 36, or age-based for kidswear.
• Whether jumps are even. Many brands use larger increments in bigger sizes.
• Which measurements do not grade. Placket width, pocket size and label position often stay the same across sizes. Say so.

If you sell in India and abroad, sizing often differs between the two. Note which size chart each colourway or market uses so the factory does not mix them.

Common mistakes that add sampling rounds

Most extra rounds trace back to something missing or vague in the tech pack. These come up again and again:

• Reference photos with no measurements. A photo shows the look, not the fit. The pattern maker will guess, and you will comment on the guess.
• Fabric described by feel only. "Soft, flowy cotton" can mean a dozen qualities. Give composition, weight and weave or knit, or send a swatch.
• No tolerances. Without them, every measurement becomes a debate at inspection.
• Changing the spec between rounds without updating the file. Comments get lost in chats and emails. Update the tech pack, raise the version number and note what changed.
• Trims left as "standard". Button size, zip length and type, elastic width and drawcord finish all affect look and cost. Specify them.
• Print placement without a fixed reference point. "Centred on chest" lands differently on every size unless you say how far down from the high point shoulder.
• Missing shrinkage information. If the garment is washed after sewing, say so. The pattern must allow for it, or the sample will come back small.
• No care label content. Composition and care instructions are often a legal requirement in your selling market. Leaving them out delays labels and packing.

If you only have a sketch or a reference photo

Many first-time brands do not have a tech pack, and that is fine. A sketch, a mood board, a photo of a garment you like or an old sample you want to improve is enough to start.

At Sourcingo, the in-house designer turns sketches, mood boards and reference photos into flat sketches and tech packs. The team sources fabric and trims and samples until the fit is right. Every style is sampled, and you sign off on fit, fabric and finish before bulk begins.

To make that conversion fast and accurate, send what you can:

• Front and back photos or sketches, plus close-ups of details
• Your target size range and fit (Indian, international or both)
• A garment that fits the way you want, or its measurements
• Fabric preference, or a swatch
• Your target cost or retail price, and quantity per style and per colour

The more of this you share upfront, the closer the first sample will be.

Keeping the tech pack alive

A tech pack is not finished when you send it. It should be updated after every sampling round so it always matches the latest approved sample.

• Keep one master file per style, with a version number and date on the cover.
• Log every change in a short revision table: what changed, why and who approved it.
• Once the pre-production sample is approved, freeze the tech pack. That version is what bulk is made and checked against.

After the first order is confirmed, Sourcingo's client portal shows your team sample approvals and comments in one place, so the latest decision is easy to find.

Questions

Updated: 12 October 2026