A custom T-shirt brief becomes useful when every sample can be checked against it. A photograph and a size chart may communicate the idea, but they do not establish which fabric, neckline, finish or decoration the factory should reproduce.
Build the development file around four decisions: what changes, how it is measured, which sample proves it, and who can approve a revision. This guide uses an adult crew-neck tee as a working example. It is a document structure, not a specification for every customer or a statement of factory capability.
Identify the parts being developed
Mark fit, fabric, trims and decoration separately as retained, revised or new. An existing body with a new chest print needs a different development scope from a new dropped-shoulder pattern. A change of fabric can require a fresh fit and decoration assessment even when the pattern outline remains unchanged.
List the target wearer, selling market, intended use, size range and expected care routine. Name a physical reference garment if available, but explain which characteristics to copy. A reference can be useful for fit while being unsuitable for the proposed fabric or neckline.
A working tech-pack register
Use the following register to connect each specification to an approval. Complete the blank fields with the supplier before ordering components. An unresolved field should be marked open, with an owner and response date, rather than treated as permission to substitute.
| File section | Information to enter | Evidence that closes it |
|---|---|---|
| Style and version | Style code, date, front/back sketches, revision summary | Supplier acknowledges the same revision |
| Body fabric | Composition, yarn preparation, knit, finished GSM, finish, color reference | Identified swatch and agreed physical tests |
| Measurements | Base size, named points, measuring diagrams, grade and tolerances | Measured fit sample and size-set record |
| Neckline and seams | Opening, finished rib height, rib quality, taping, seam and hem construction | Inside/outside detail photographs and washed sample |
| Decoration | Final file, dimensions, placement origins, method and color standard | Actual-fabric strike-off and decorated garment |
| Labels and packing | Artwork version, placement, market, folding and unit identification | Proofs and packed production-equivalent sample |
| Order scope | Color/size quantities, required milestones, delivery basis | Quotation tied to this file version |
Make measurement instructions reproducible
Define chest width as a flat measurement at a named position below the armhole. Define body length from a named shoulder or neck point to the hem. State whether rib is included in neckline measurements and whether sleeve length follows the shoulder seam or starts at the neck. Small differences in starting points can create disagreements larger than the sewing variation being investigated.
Record the garment’s condition: relaxed, unwashed or washed using the agreed procedure. State the units once and use them throughout. Separate finished garment targets from body measurements used to describe the intended customer. A garment measurement is not a consumer body-size claim.
Ask for tolerances by critical point rather than applying one number everywhere. Neck opening, body width and overall length do not have identical functional consequences. The supplier should review whether the proposed limits are practical for the chosen construction before the purchase order is released.
Give construction its own approval
Show shoulder tape, side-seam construction, hem depth and neckline attachment in detail views. If the buyer does not know the appropriate stitch, request a proposal with a sample instead of inventing a stitch specification. Once accepted, record the chosen construction so bulk does not depend on a verbal description such as premium finish.
Treat the body and neck rib as a system. Changing the body weight, finish or stretch can change how the collar sits. Test the assembled garment after care, not just a loose rib strip. Inspect seam appearance, recovery and the ease of putting the tee on and taking it off.
Separate fit approval from production approval
A fit sample can close proportions while using a substitute color, provided the substitution and remaining approvals are recorded. It cannot establish bulk shade, final print performance or the correctness of labels that have not arrived.
The pre-production sample should represent the proposed bulk material, construction, decoration and trims. If anything remains substituted, identify the exact evidence still required and withhold approval of that item. Keep a dated reference sample and matching measurement sheet with both parties.
Before authorizing bulk, review the size extremes as well as the base size. A successful medium does not prove that the sleeve opening, neck access or body balance works across the range. Put each correction into the master document rather than leaving conflicting instructions in email attachments.
Control changes after approval
Maintain a short change log: requested change, reason, affected files, quotation impact, sample required and approver. A new print position may change folding and packing. A composition change affects labeling and may alter the care routine. A revised neckline can invalidate a previously approved grade.
Close the file with one release note identifying the approved revision and samples. Ask the supplier to acknowledge what bulk production will follow. This creates an actionable inspection reference and leaves fewer decisions to be reconstructed when the finished order arrives.
Related purchasing guidance
For the next purchasing checks, see basic tee quotation inputs and custom apparel tech-pack requirements.
