This assumes you know what a tech pack is and why a factory needs one. What follows is the production order — what to do first so that the thing you do fourth does not invalidate it.
1. Fix the product definition first
Before a single line is drawn, write down four things: what the product is, who it is for, the size range, and the target landed cost. Add the category, because the category decides which compliance sections you will need at step eight.
This step feels like paperwork and is the one that saves the most time. The size range in particular: deciding to add XXL after you have graded is not adding a column, it is revisiting the grade rule on every point of measure, because the increments at the top of a range are rarely the same as the ones in the middle. The target cost matters here for the same reason — it constrains materials, and materials constrain construction.
2. Draw the technical flat
A technical flat is a proportional line drawing of the product as if laid flat: front and back, no shading, no model, no styling, no fabric texture. It is a diagram, not an illustration. Where the product has a lining, an inside detail or a construction that is invisible from outside, it gets its own view.
Draw every seam, every topstitch line and every closure, because the flat is what the construction callouts at step six attach to. A flat that omits a seam has no place to hang the instruction describing it, and the seam quietly stops existing.
The test for a good flat: hand it to someone who has never seen the product and ask them to describe the back. If they can, it is proportional and complete. If they ask which way round it goes, it is an illustration.
3. Build the points-of-measure table
Every measurement gets four things: a code (so the callout on the flat and the row in the table refer to each other), a stated method, a value at your sample size, and a tolerance.
The method column is not optional and is the single most-skipped field in the whole document. "Chest: 20½" is not a specification. "Chest, measured 1 inch below the armhole, across, doubled: 20½" is. The same three words of ambiguity are what produce a sample that is technically to spec and visibly wrong.
Measure a real reference product rather than inventing numbers. If you are developing something that does not exist yet, measure the closest thing you own and adjust from there — a table built from a physical object is right about proportion in a way a table built from arithmetic rarely is.
4. Grade across the size range
Grading is applying an increment to each point of measure across each size. The trap is that it is per measurement, not per garment. A chest might grow 1½ inches between sizes while a neck grows ¼ and a sleeve length grows ½. Apply one increment to everything and the largest size in the run comes back with a collar nobody can get over their head.
If you have a reference product that is already graded well, take the increments from it. Otherwise the factory can often supply standard grade rules for the category — this is one of the places where asking them is genuinely the right move, because grade rules are regional and fit-block specific.
5. Write the bill of materials
The BOM lists every component that arrives at the factory as a separate purchase. For each one: composition, weight or gauge, colour reference, supplier if you are nominating it, placement, and consumption per unit.
- Shell and lining — fibre content, weight (gsm or oz), construction, finish.
- Thread — type and weight, and where it differs across the product.
- Interfacing and interlining — including where it is applied, which is easily forgotten.
- Trims and closures — zips by size and type, buttons by ligne, hardware by finish.
- Labels — main, care, size, and any compliance label the market requires.
- Packaging — polybag, hangtag, tag attachment, carton.
The reason to be exhaustive is costing, not pedantry. A component missing from the BOM is a component missing from the quote, and it reappears later as a price increase you have no grounds to challenge.
6. Add construction callouts
Annotate the flat with seam types, stitch class and density, edge finishes, topstitch distances and reinforcement points. Anywhere the product takes stress — pocket corners, armhole, strap attachment, crotch — say what happens there.
Specify the outcome and the tolerance, not the method. Dictating a technique the factory's machines cannot hold gets it either silently ignored or priced as a special operation. Telling them the seam must survive a stated test, and letting them reach it on the equipment they have, gets you the result at the price you costed.
7. Specify colourways, labels and packaging
Each colourway needs a reference standard per component — a physical or numbered standard, not a screen colour. A hex value is a description of light on your monitor and says nothing about how a dye behaves on a given fibre; the same reference on cotton and on polyester will not match, which is why the standard is stated per component rather than per garment.
Labels need artwork, dimensions, placement measured from a named point, and attachment method. "Neck label, centred, 1 inch below the neckline seam, sewn on all four sides" — the difference between that and "neck label" is a whole production run.
Packaging is the section people leave until it is urgent. Fold method, polybag size, barcode placement, carton pack ratios. A retailer that receives the goods folded differently from the way its planogram assumes will charge you for it.
8. Add compliance, then version and send
State the testing required, the fibre content and country-of-origin copy, and any age grading, warning text or category-specific requirement. This is jurisdictional — what a market requires is a legal question about where you are selling, not a design question, and it is worth confirming rather than assuming.
Then, before it leaves: put a revision number and a date on the cover, and increment it on every change. This is the cheapest line in the document and prevents the most expensive failure mode there is — a factory cutting from revision 2 while you are approving revision 4, with nothing on either copy to reveal it. Send as PDF, because factories print tech packs and PDF prints identically everywhere.
Mistakes that cost a sample round
| Mistake | What it produces | Fix |
|---|---|---|
| Measurements with no method | A sample that is to spec and visibly wrong. | A "how to measure" column on every row. |
| No tolerance column | Either nothing can be rejected, or nothing can pass. | State ± per measurement. Tighter where it shows. |
| One grade increment for everything | Unwearable sizes at both ends of the range. | Grade per point of measure. |
| Colour given as a hex value | Trim and shell that do not match. | A reference standard per component. |
| A mood photo used as the flat | The factory interprets the silhouette. | A proportional line drawing, front and back. |
| No revision number | Two versions in production at once. | Revision and date on the cover, incremented every change. |
| Packaging left until later | Chargebacks from the retailer. | Fold, bag, barcode and carton in the first send. |
Doing it faster
Written by hand from scratch, a first tech pack for a simple product realistically takes a full working day and often more — most of it on the flat and the graded table. The second one in the same category goes faster, because grading rules and most of the BOM carry over. The tenth is mostly editing.
That curve is the reason the whole category of tech pack software exists: templates to stop you rebuilding the structure, PLM to stop you rebuilding the library, and generators to stop you drawing the flat. What none of them remove is the judgement in steps one, four and six — the size range, the grade rule and the construction are still calls somebody has to make.
DreamPack Studio takes the description of a product and writes the pack around it: the flat drawn from your design, the measurements, the materials, the labels and the safety copy, inside your brand's own colours and rules.
Common questions
How long does it take to make a tech pack?
By hand from scratch, a first pack for a simple product is realistically a full working day or more, most of it on the flat and the graded table. Later styles in the same category go faster because grading rules and the bill of materials carry over.
Do I need Illustrator or CAD to make a tech pack?
No. Illustrator is traditional for flats because it draws clean vector line art, but nothing in a tech pack requires it. The factory needs a proportional, unambiguous drawing and a complete specification in a format they can open and print.
What is the most common tech pack mistake?
Measurements without a stated method — "chest: 20½" means nothing until the pack says where the chest is measured and whether the figure is flat or circumference. Second is a measurement table with no tolerance column.
Should I send the tech pack as a PDF?
Yes — it prints identically everywhere, and factories print tech packs. Whatever you send, keep the revision number and date on the cover so the copy above the cutting table can be checked against the copy in your inbox.