A founder ordered a satin evening dress from a mid-size China factory, sent a moodboard and a sketch, and approved a sample that looked perfect in the photos. The production run came back with seams that pulled at the hips, a neckline that gaped, and a zipper that caught on the lining. The factory pointed to the approved sample; the founder had no written spec to argue against. That gap, between a sample that looks right and a spec that defines right, is what this article walks through. You will leave able to write a tech pack that a factory can quote and a QC inspector can enforce.
Start With the Garment Map
Before any factory touches fabric, your tech pack must carry a garment map: a flat sketch with every panel numbered, every seam type named, and every measurement point marked. A factory in China can cut and sew from a photo, but it will grade, price, and inspect from the map. One founder I worked with skipped the map and paid for three rounds of samples that each fixed one error the previous round introduced. The map is the single document that turns a vague request into a quoteable spec, and it costs nothing but drawing time.
You can produce it in Adobe Illustrator or Procreate, export as PDF, and place it on page one of the pack.
Why a Garment Map Prevents Quote Inflation
A factory’s first response to an unclear tech pack is to inflate the quote. The factory assumes the risk of unclear construction and prices it in. A numbered map lets the merchandiser count operations, assign line time, and quote on facts. In one case, a clear map cut a quote by 22 percent because the factory could see the bodice was a simple princess seam, not a complex boned structure.
How to Number Panels and Name Seams
Number every panel on the sketch, front and back. Name every seam: "SS" for side seam, "CB" for center back, "PS" for princess seam. Add arrows to every point of measurement: HPS to bust, HPS to waist, across shoulder, sleeve length. A factory in Hangzhou will understand "HPS" instantly; a junior merchandiser in a smaller shop may not, so spell it out once: "HPS = High Point of Shoulder." That single line prevents a sample built from shoulder to waist instead of HPS to waist, a difference of 2 cm that ruins fit.
List Construction Details in the BOM
The bill of materials is where founders lose money. You must list every component, its spec, its placement, and its supplier if you provide it. For a satin dress, the BOM must specify shell fabric weight in GSM, lining weight, zipper type and length, hook and eye size, thread type, care label, hangtag, and polybag. A factory will substitute if a spec is missing, and the substitute will be the cheapest option that fits the word. "Lining" without a weight becomes 60 GSM polyester instead of the 90 GSM you wanted; the dress clings and shows every line underneath.
Specify Fabric With Numbers, Not Names
Write "100% polyester satin, 135 GSM, 58/60" width, peach-skin finish." Do not write "satin." One founder wrote "satin" and received a stiff bridal satin instead of a fluid evening satin. The factory had quoted on bridal because it was cheaper and the tech pack did not forbid it. A GSM spec and a finish description give the factory a target and give you a basis to reject a substitute.
How to Specify Trims Without Overpaying
For trims, give a size, a material, and a finish. "Invisible zipper, 18 inch, nylon coil, silver pull." Do not write "zipper." A factory will quote a 5 cent metal zipper that snags satin and costs you returns. Specify the hook and eye as "size 0, black, sew-on." Each line in the BOM should be a sentence a supplier can read and source without asking a question. Every question a factory asks is a day of delay and a chance for the factory to choose for you.
Measurement Charts With Tolerances
A measurement chart without tolerances is an invitation to a factory to deliver whatever it can. You must list every point of measurement, the target, and a tolerance. For woven garments, plus or minus 0.5 cm is standard for most points; for knits, plus or minus 1 cm. A founder who set all tolerances at zero received a production run where half the dresses were 0.3 cm off and the factory refused to remake because the tech pack allowed no deviation. Set tolerances that reflect real sewing capability, and a factory will respect them.
How to Set Tolerances That Protect Fit
Set tighter tolerances at points that affect fit and appearance: bust, waist, and hip at plus or minus 0.5 cm. Set looser tolerances at points that are less visible or more variable: sleeve opening, hem sweep, at plus or minus 1 cm. For a satin dress, the neckline tolerance must be plus or minus 0.3 cm; a gaping neckline is a return. Write the tolerance in a column next to the target, and add a note: "Measurements outside tolerance are rejectable." That note gives your QC inspector the authority to hold a shipment.
Why You Must Include a Size Run
Even if you start with one size, include a size run in the tech pack. A factory will need to grade to other sizes eventually, and a size run shows the factory you understand grading. It also lets the factory quote grading costs upfront. One founder who omitted a size run paid 40 percent more for grading because the factory treated it as a new project. A size run is a table: sizes across the top, measurements down the side, numbers in the cells. It takes an hour to build and saves weeks of negotiation.
Stitch and Seam Specifications
A factory will choose the cheapest stitch that holds unless you specify. For a satin dress, the side seams must be a lockstitch, not a chain stitch, because chain stitch unravels. Specify the stitch type by number: "301 lockstitch" for seams, "304 zigzag" for raw edges. Specify stitches per inch: "14 SPI." A factory that runs 10 SPI to save time will deliver a seam that pulls apart under stress. These specs are in the tech pack, not in a conversation, because conversations are forgotten and tech packs are signed.
How to Specify Stitch Density for Satin
Satin shows every needle mark. Specify a fine needle, size 9 or 11, and a stitch density of 14 to 16 SPI. A coarse stitch at 10 SPI will pucker the seam and leave visible holes. Add a note: "Use ballpoint needle to prevent snagging." One founder who skipped this note received a dress with runs along every seam because the factory used a sharp needle on a delicate weave.
Seam Allowances and Construction Sequence
Specify seam allowance for every seam: "1 cm on side seams, 1.5 cm on CB seam." A factory will cut allowances to save fabric if you do not specify, and a 0.5 cm allowance on a satin side seam will fray and fail. Add a construction sequence: "1. Sew princess seams. 2. Attach lining to shell at neckline. 3. Insert zipper. 4. Sew side seams." The sequence prevents a factory from sewing the zipper before the lining is attached, which makes the zipper visible and the dress unsalable.
Labeling, Packaging, and Shipping Marks
A tech pack must carry labeling and packaging specs or the factory will choose. Specify the care label content, the size and placement of the brand label, the hangtag design and attachment, and the polybag type. One founder who omitted polybag spec received dresses in 1 mil bags that tore in transit; the dresses arrived scratched and dusty. Specify "3 mil clear polybag, no print, with adhesive flap." Specify the carton size and the shipping mark: "Carton 60x40x40 cm, gross weight under 15 kg, mark with PO number and size ratio." These specs are not glamorous, but they prevent the most common production disasters.
How to Specify a Care Label for Satin
A care label for a satin dress must read: "100% Polyester. Machine wash cold, gentle cycle. Do not bleach. Hang dry. Cool iron if needed." If you omit the care label content, the factory will print a generic label that may say "dry clean only," which kills sales for an evening dress that customers want to wash at home. Write the full care label text in the tech pack, and the factory will print it exactly.
The Approval Process: How to Use the Tech Pack in Sample Development
A tech pack is not a document you send and forget. You use it to drive the sample cycle. When the factory sends a first sample, you check it against the tech pack, not against a photo. You measure every point, check every trim, inspect every stitch. You write comments on the tech pack itself: "Bust 2 cm large, reduce to target. Zipper pull wrong color, change to silver. Lining too stiff, reduce GSM to 90." You send the marked tech pack back, and the factory revises. The second sample should match the tech pack exactly. If it does not, you have a written record to enforce a remake at the factory’s cost.
How Many Samples Before Production
Most founders need two to three samples. The first sample checks fit and construction. The second sample checks revisions and fabric. The third sample, the pre-production sample, is the final check before bulk. You approve the pre-production sample in writing, and that sample becomes the standard for bulk production. A factory will use the approved sample as the reference, so your tech pack and the approved sample must match. If they do not, the factory will follow the sample, not the pack. That is why the pack must be right before the first sample is cut.
Common Tech Pack Errors That Cost Money
The most common error is a missing BOM line. A factory will not ask; it will substitute. The second most common error is a tolerance set to zero. The factory will deliver whatever it can, and you will have no basis to reject. The third is a missing construction sequence. The factory will sew in the order that is fastest, not the order that is correct. The fourth is a missing label spec. The factory will print a generic label that may not meet legal requirements in your market. Each of these errors costs a sample round, and each sample round costs two to four weeks and hundreds of dollars.
How to Avoid the "Looks Right" Trap
A sample that looks right in a photo may not be right. You must measure it. A founder approved a sample that looked perfect, but the bust was 3 cm large. In production, the factory held the 3 cm, and the dresses were too large for the target customer. The founder had no recourse because the tech pack had no tolerance and the sample was approved. Measure every sample, compare to the tech pack, and approve in writing only when the numbers match. A photo is not an approval; a signed tech pack is.
Tools and Templates for Founders
You do not need expensive software to write a tech pack. You can build one in Google Sheets or Excel. Page one is the garment map. Page two is the BOM. Page three is the measurement chart with tolerances. Page four is construction and stitch specs. Page five is labeling and packaging. Five pages, clearly written, will get you a quote and a sample that matches your vision. You can find free templates online, but the value is in the content, not the format. Write specs that a factory can source from and a QC inspector can measure against, and you will have a tech pack that works.
What to Do If You Are Not Technical
If you cannot write a tech pack yourself, hire a technical designer. The cost is 200 to 500 dollars for a simple garment, and it is the best money you will spend. A technical designer will translate your sketch into a factory-ready spec and will catch errors you would miss. One founder who hired a technical designer saved 3,000 dollars in sample fees because the first sample was correct. The investment in a tech pack is small compared to the cost of a production run that fails.
Final Checklist Before You Send the Tech Pack
Before you send the tech pack to a factory, check that it has a garment map with numbered panels and named seams. Check that the BOM lists every component with a spec. Check that the measurement chart has tolerances. Check that stitch and seam specs are present. Check that labeling and packaging are specified. Check that a size run is included. If any of these are missing, do not send the pack. Fix the gap, and you will save time and money in the sample cycle. A complete tech pack is the difference between a factory that delivers what you want and a factory that delivers what it can.
What to send us
If the specifications above match what you are sourcing, send your tech pack to Orange Sea Clothing. If the pack is not written yet, sketches and a reference sample are enough to start — sample development covers the design review, fabric and trim sourcing, pattern making and the first prototype, so you see fit and construction before you commit to a production run.
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