A bill of materials (BOM) is the complete list of materials needed to make a garment style. It is the basis for material booking, costing, store receiving and production. A good BOM prevents missing trims, wrong colors and shortages at the line.
What goes in a BOM#
| Category | Examples |
|---|---|
| Fabrics | Main fabric, contrast, rib, lining, interlining, pocketing |
| Sewing trims | Thread, zippers, buttons, snaps, elastic, tapes, drawcords, eyelets |
| Labels | Main label, size label, care label, country of origin, special labels |
| Decoration | Print artwork, embroidery thread, heat transfers, patches |
| Packing | Hangtags, price tickets, stickers, polybags, tissue, hangers, cartons, carton stickers |
Columns#
| Column | Purpose |
|---|---|
| Item | Material name |
| Description and specification | Composition, size, finish, color reference, supplier article number |
| Placement | Where it is used on the garment |
| Unit | kg, m, pcs, cones |
| Consumption per garment | Quantity per piece |
| Wastage % | Allowance for losses |
| Color and size breakdown | For materials that vary by color or size |
| Supplier | Nominated or selected supplier |
| Unit price | For costing |
| Total required | Calculated quantity for the order |
Calculating quantities#
For materials that change by color or size (such as size labels or color-matched thread), calculate each line separately.
Worked example: size labels#
Order: 6,000 T-shirts in the size ratio S 1 : M 2 : L 2 : XL 1. Wastage 3%.
| Size | Quantity | Labels with 3% wastage |
|---|---|---|
| S | 1,000 | 1,030 |
| M | 2,000 | 2,060 |
| L | 2,000 | 2,060 |
| XL | 1,000 | 1,030 |
Ordering 6,180 labels without a size breakdown would leave the store unable to issue the right labels.
Consumption sources#
- Fabric: from the marker or consumption calculation. See fabric consumption.
- Thread: from seam lengths and ratios. See thread consumption.
- Trims: count per garment from the tech pack (for example, 7 buttons on a shirt front plus 2 on cuffs plus 1 spare).
- Packing: from packing instructions (for example, one polybag per garment, one carton per 24 pieces).
Minimum order quantities and rounding#
Suppliers sell in units such as cones, rolls, boxes of 1,000 or cartons of 50. Round up the required quantity to the supplier's unit, and note minimum order quantities, which can make small orders expensive.
Keeping the BOM accurate#
- One version shared across merchandising, store, production and costing.
- Update after every change in the tech pack or buyer comment, with a revision date.
- Link to approvals: record which trims are approved and when.
- Check at the PP meeting against the approved sample and trim card.
Common mistakes#
- Missing small items, such as spare buttons, security tags or tissue paper.
- Color-matched items ordered in one color for a multi-color order.
- Wastage added twice (in consumption and again as a percentage).
- Old version of the BOM used by the store.
- Packing materials forgotten until finishing.
The BOM template has these columns ready.
Related guides#
- Garment costing: pricing each BOM line in the cost sheet.
- Time and action plan: booking materials in time for the plan.
- Pre-production meeting: checking the BOM against the approved sample and trim card.
- Pantone color guide and its application in textile: recording color references for fabric and trims.
Frequently asked questions#
Is a BOM the same as a trim card? No. The trim card is a physical board with approved trim samples. The BOM is the list with specifications and quantities. Both should match.
Who maintains the BOM? Usually the merchandiser, with input from the technical team and store.