The Standards You Should Name in Your Tech Pack
Chinese fabric mills and dye houses operate to GB standards, not AATCC or ISO. Naming the standard removes ambiguity. For color fastness, cite GB/T 3920 for rubbing fastness and GB/T 5713 for water fastness. For dimensional stability, cite GB/T 8629. For fabric weight, cite GB/T 4669. When you name the standard, the factory knows the test method and the acceptance threshold, and you can verify the results with a third-party lab if the fabric fails. A tech pack that says "color fastness good" is not a spec; a tech pack that says "GB/T 3920 Grade 4" is a contract.
A two piece set with a fitted top and a flared skirt needs a fabric that moves with the body but returns to shape. Specify the elastane content as a percentage, and specify the stretch ratio as a number. For a form-fitting top, 5% elastane with a 20% stretch ratio is typical. For a flared skirt, 2% elastane with a 10% stretch ratio is enough. The recovery rate matters as much as the stretch. A fabric that stretches 20% but recovers only 15% will bag at the knee after one wear. Ask the mill for a stretch and recovery test report, and specify the acceptance threshold in your tech pack.
Opacity is a function of fabric weight, yarn count, and weave density. A 120 g/m² fabric with a high yarn count will be more opaque than a 150 g/m² fabric with a low yarn count. For a dress that does not require a lining, specify a minimum opacity rating. The standard test is ASTM D5826, which measures the percentage of light transmitted through the fabric. For an unlined dress, specify a light transmission of less than 5%. For a lined dress, the shell fabric can have a higher transmission rate, but the lining must be below 2%. These numbers are not guesses; they are measurable, and they prevent the "can see through it" complaint that triggers a customer return.
A satin evening dress has three critical fabric specs: the drape, the luster, and the seam slippage. Drape is a function of weight and weave; specify the weight and the weave (charmeuse, duchess, or crepe-back satin). Luster is a function of the yarn and the calendering process; specify the luster level as low, medium, or high, and ask for a fabric swatch that matches your reference. Seam slippage is the tendency of the yarns to separate at the seam under tension; for a fitted dress, specify a seam slippage of less than 5 mm at 120 N, tested to GB/T 13772. If the fabric fails this test, the side seams will pop when the wearer sits.
After the mill submits the pre-production fabric, run three tests before you approve the bulk order. First, weigh a 10 cm x 10 cm swatch on a precision scale and multiply by 100 to get the GSM. Second, cut a 5 cm wide strip, clamp it in a tensile tester, and pull to 120 N to measure seam slippage. Third, wash a swatch at 40°C and measure the dimensional change. If any of these three numbers drift from your approved sample by more than the tolerance in your tech pack, reject the lot. The cost of a test swatch is a fraction of the cost of a production run that fails inspection.
How to Write a Tech Pack That a Chinese Mill Can Execute
A tech pack is a contract, not a wish list. For each fabric, specify the fiber composition, the yarn count, the fabric weight, the weave, the stretch ratio, the recovery rate, the color fastness standard, the dimensional stability standard, and the opacity rating. For each trim, specify the material, the size, and the color. For each seam, specify the stitch type, the stitch density, and the seam allowance. Attach a reference swatch for every fabric and trim, and label each swatch with the spec it represents. A tech pack with a reference swatch and a named standard is a document a factory can execute; a tech pack without them is a document a factory will interpret.
Ambiguity in a tech pack is not a risk; it is a certainty of cost. If you do not specify the fabric weight, the mill will choose the weight that is cheapest to produce, not the weight that matches your sample. If you do not specify the color fastness standard, the dye house will use the dye that is cheapest to apply, not the dye that meets your customer’s expectation. If you do not specify the stretch ratio, the knitting mill will set the machine to the default, not to the ratio that fits your pattern. Every ambiguity in your tech pack is a decision you delegate to a factory whose priority is cost, not quality. The cost of a spec is the cost of control.
For a private label collection of 10 dresses, you need 10 fabrics, or you need one fabric that works for 10 silhouettes. The second option is more efficient. Choose a fabric with a weight of 150 g/m², a 3% elastane content, and a medium yarn count. This fabric will drape enough for a bias-cut dress, hold enough for an A-line dress, and stretch enough for a fitted top. Source the fabric in 5 colors, and cut 10 silhouettes from the same roll. This approach reduces the minimum order quantity per fabric, simplifies the production planning, and lowers the inventory risk. A private label collection is not 10 fabrics; it is one fabric in 10 shapes.
Hand feel is subjective, but the properties that create it are measurable. Softness is a function of the yarn count and the finishing process; a higher yarn count and a enzymatic wash produce a softer hand. Smoothness is a function of the calendering pressure; a higher pressure produces a smoother surface. Drape is a function of the weight and the stiffness; a lower weight and a lower stiffness produce a higher drape. Specify these properties in your tech pack with measurable values, and ask the mill for a test report. A fabric that feels right in the hand is a fabric that sells in the store.
How to Manage Color Drift in a Satin Evening Dress
Satin fabric shows color drift more than any other weave because the luster highlights the difference between dye lots. To manage color drift, specify the color with a Pantone reference and a physical swatch, and ask the dye house to submit a lab dip for approval before the bulk dyeing. When the lab dip arrives, compare it to your reference under a D65 light source, not under office lighting. If the lab dip is outside the acceptable tolerance, reject it and request a new one. Do not approve a lab dip that is "close enough"; close enough in the lab is a return in the store.
A fabric-first dress collection has a different timeline than a design-first collection. In week one, you source the fabric and test the swatch. In week two, you approve the lab dip and the hand feel. In week three, you cut the sample from the approved fabric. In week four, you fit the sample and adjust the pattern. In week five, you approve the pre-production sample and place the bulk order. In week eight, the bulk fabric arrives, and cutting begins. This timeline is predictable because the fabric is fixed; a design-first timeline is unpredictable because the fabric is variable. Control the fabric, and you control the timeline.
A mill respects a spec that is specific, measurable, and verifiable. Specific means you name the fiber, the yarn count, the weight, and the weave. Measurable means you cite the test standard and the acceptance threshold. Verifiable means you attach a reference swatch and require a test report on the pre-production sample. A spec that says "polyester satin, 150 g/m², GB/T 4669, reference swatch attached" is a spec a mill will respect. A spec that says "satin fabric, good quality" is a spec a mill will ignore. The language of sourcing is the language of measurement, not the language of marketing.
The minimum order quantity (MOQ) for a private label fabric is a function of the dye lot, not the knitting or weaving lot. A knitting mill might produce 500 kg of fabric in one lot, but a dye house might require 1,000 kg to start a dye lot. For a collection of 10 dresses, you need 200 kg of fabric, which is below the dye lot MOQ. To meet the MOQ, you can either order more fabric and hold inventory, or you can share the dye lot with another brand. The second option is how private label sourcing works in practice; you buy a portion of a dye lot that another brand has already commissioned. This approach reduces your MOQ but requires you to accept the color and the hand feel of the existing lot.
Verification is a three-step process: test, compare, and approve. Test the pre-production fabric for weight, color fastness, dimensional stability, and stretch. Compare the test results to the specs in your tech pack. Approve the fabric only if every test result is within the tolerance. If a test result is outside the tolerance, reject the fabric and request a new lot. Do not approve a fabric that is "close enough"; close enough in the lab is a defect in the field. The cost of a test is $50; the cost of a defective production run is $5,000. Verification is not an expense; it is an insurance policy.
The Fabric Sourcing Strategy for a Two Piece Set
A two piece set has two garments that must match in color and hand feel. To ensure a match, source the fabric for both pieces from the same dye lot. If the top and the skirt are from different dye lots, the color will differ, and the set will look mismatched. In your tech pack, specify that the top and the skirt must be cut from the same dye lot, and require the factory to submit a cutting plan that shows the dye lot number for each piece. This requirement adds a step to the production process, but it prevents the customer complaint that the set does not match.
The hand feel of a satin evening dress is a function of the finishing process, not the fiber. A polyester satin can feel like silk if it is finished with a softener and a calendering process. To manage the hand feel, specify the finishing process in your tech pack: "softener treatment, calendering at 80°C, 50 kN pressure." These parameters are measurable, and the mill can adjust them to match your reference swatch. A satin that feels stiff is a satin that was not calendered; a satin that feels limp is a satin that was over-softened. The finishing process is the last step in fabric production, and it is the step that determines the hand feel.
The cost of a private label dress fabric is the sum of the fiber cost, the yarn cost, the weaving or knitting cost, the dyeing cost, and the finishing cost. The fiber cost is a function of the market price; the yarn cost is a function of the yarn count; the weaving cost is a function of the fabric weight; the dyeing cost is a function of the color depth; the finishing cost is a function of the process. To reduce the cost without reducing the quality, adjust the yarn count and the fabric weight, not the fiber or the dye. A higher yarn count and a lower fabric weight produce a fabric that is cheaper to produce but still meets your spec.
A tech pack for a Chinese factory should be in English and Chinese, with the Chinese translations provided by a native speaker. The measurements should be in centimeters, not inches. The standards should be GB standards, not ASTM or ISO. The reference swatches should be attached to the tech pack, not sent separately. The approval process should be documented in the tech pack, with a sign-off block for each stage: fabric, trim, sample, and bulk. A tech pack that follows these conventions is a tech pack that a Chinese factory will execute without questions; a tech pack that does not is a tech pack that will generate a stream of emails and delays.
The Fabric Sourcing Checklist for a Private Label Dress
Before you place a bulk order for a private label dress fabric, run through this checklist:
- Fiber composition specified? Yes/No
- Yarn count specified? Yes/No
- Fabric weight specified? Yes/No
- Weave specified? Yes/No
- Stretch ratio specified? Yes/No
- Recovery rate specified? Yes/No
- Color fastness standard cited? Yes/No
- Dimensional stability standard cited? Yes/No
- Opacity rating specified? Yes/No
- Reference swatch attached? Yes/No
- Lab dip approved? Yes/No
- Pre-production sample tested? Yes/No
- Test results within tolerance? Yes/No
If any answer is "No," do not place the order. The checklist is not a formality; it is the difference between a production run that ships on time and a production run that sits in the factory while you argue about who is responsible for the defect.
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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