Garment bill of materials (BOM): how to write one for your tech pack
What a clothing BOM is, what to list for fabrics and trims, how to specify supplier, colour and quantity, and an example BOM for a T-shirt.
Updated 1 October 2026 · By Hem Apparel
A bill of materials (BOM) lists every material that goes into a garment: fabrics, trims, labels and packaging. Factories use it to cost the garment and to order materials, so an incomplete BOM leads directly to a wrong price.
What a BOM line contains
- Item and placement: what it is and where it goes, for example 'main fabric, body and sleeves'.
- Description: fibre content, construction and weight, or the trim's size and material.
- Colour: Pantone code or supplier colour name.
- Supplier or source: who provides it, if you have a preference.
- Quantity per garment: metres, pieces or grams, including a wastage allowance for fabric.
- Notes: finishing, certifications, tolerances.
Example: basic T-shirt BOM
| Item | Description | Colour | Qty per garment |
|---|---|---|---|
| Main fabric | 100% combed cotton single jersey, 200 GSM | Off-white 11-0602 TCX | 0.9 m (at 1.5 m width) |
| Neck rib | 1×1 cotton/elastane rib, 280 GSM | Match body | 0.04 m |
| Sewing thread | Spun polyester 40/2 | Match body | 1 cone per 150 pieces |
| Neck tape | Cotton tape, 1.5 cm | White | 0.5 m |
| Main label | Woven, 4 × 2 cm | Black on white | 1 piece |
| Care label | Printed satin | White | 1 piece |
| Polybag | LDPE, 25 × 35 cm, with warning text | Clear | 1 piece |
The quantities above are illustrative. The factory calculates real consumption from your pattern and marker, so ask them to confirm.
Fabric consumption and wastage
Fabric use depends on the pattern, size range and fabric width. Factories add a wastage allowance, often 5–10%, for cutting loss. Always state fabric width as well as weight, because a narrower fabric needs more length.
Common BOM mistakes
- Leaving out thread, labels or packaging.
- Listing 'cotton' without fibre content and GSM.
- Specifying colours by name only.
- Not stating where each trim goes.
- Changing materials after the sample is approved without telling the factory.
Download an example tech pack
A worked T-shirt example with sketches, graded measurements, materials and production notes. The values are illustrative; adapt and approve them with your factory before production.
Download the example PDF