Trims standards: sizes, units and the numbers buyers quote
One ligne is 0.635 mm. One gross is 144 pieces. US childrenswear coatings must stay under 90 ppm lead. These are the fixed numbers behind every trim RFQ — collected here so nobody has to dig them out of a standard document mid-negotiation.
Button sizes: ligne to millimetres
Ligne (L) is the trade unit for button diameter across every material — resin, shell, horn, metal alike.
| Ligne | Millimetres | Typical use |
|---|---|---|
| 1L = 0.635 mm | — | Conversion formula |
| 14L | 8.9 mm | Small shirt buttons |
| 16L | 10.2 mm | Shirts |
| 18L | 11.4 mm | Shirts / knitwear |
| 20L | 12.7 mm | Shirts / kidswear |
| 24L | 15.2 mm | Coats / outerwear |
Counting units: pieces, dozens, gross
MOQs are quoted per size and per colour, normally in gross.
| Unit | Conversion | Note |
|---|---|---|
| PCS | 1 piece | Base unit |
| Dozen | 1 dozen = 12 PCS | — |
| Gross | 1 gross = 144 PCS | The unit button MOQs are quoted in |
| Inch | 1 inch = 25.4 mm | Zipper lengths |
The hard numbers
Acceptance values buyers write into spec sheets and POs. Where the buyer's manual is stricter than the industry norm, the buyer's manual wins.
| Item | Value | Basis / note |
|---|---|---|
| Lead content, coatings | < 90 ppm | US CPSIA / 16 CFR 1303 limit for childrenswear coatings |
| Nickel release, metal parts | EN 1811 / EN 12472 | For parts in prolonged skin contact |
| Snap fastener opening force | 10 N/20 s or 17 N/10 s | Per the standard the buyer specifies; measured on the actual garment fabric |
| Webbing breaking strength, load-bearing | ≥ 2,000 N | Safety and climbing applications |
| Webbing breaking strength, decorative | ≥ 300 N | Standard decorative webbing |
| Webbing shrinkage | ≤ 3% (warp and weft) | After pre-shrink setting |
| Webbing width tolerance | ± 0.2 mm | — |
| Colour fastness | ≥ grade 3–4 | Rub, wash and perspiration |
| Salt spray, plated metal parts | 24 h standard; 48 h and above on request | ASTM B117; longer hours are a special requirement priced as its own line |
Ten physical tests every zipper report uses
Test names follow ASTM D2061 — the same names appear on quotation sheets and third-party reports.
| # | Test | What it proves |
|---|---|---|
| 1 | Chain crosswise strength | Base strength of the chain |
| 2 | Retainer crosswise strength | Separating (open-end) zippers |
| 3 | Bottom stop holding strength | Close-end zippers |
| 4 | Top stop holding strength | — |
| 5 | Slider locking strength | Stops the slider sliding open |
| 6 | Element (tooth) holding strength | Single-tooth retention |
| 7 | Slider deflection strength | Slider assembly rigidity |
| 8 | Slider pull-off strength | — |
| 9 | Slider smoothness (operating force) | Quantifies the smooth feel |
| 10 | Reciprocating durability | Open-close cycle life |
Wash process decides the surface finish
A finish that survives a carton can still die in a laundry. Match the plating system to the garment's wash before sampling, not after bulk.
| Wash process | Requirement for plating / coating |
|---|---|
| Normal wash | Standard lacquer is sufficient |
| Stone wash | Abrasion-resistant lacquer — ordinary plating will be scoured dull |
| Enzyme wash | Enzyme-resistant finish required |
| Sand blast / spray | Impact-resistant finish — the surface loses gloss easily |
| Stone wash + heavy enzyme | The strictest case: high-temperature acid-resistant lacquer is mandatory |
US / UK trade terms quick table
The same part under two names — the fastest way to lose credibility on a spec sheet is mixing them up.
| Trim | US term | UK term | Note |
|---|---|---|---|
| Trims (collective) | trims & accessories / notions | trims / haberdashery | Notions is US sewing-trade usage |
| Bill of materials | BOM | BOM | Every trim listed line by line in the tech pack |
| Zipper | zipper | zip | The largest US/UK difference |
| Hangtag | hangtag | swing tag | — |
| Snap fastener | snap button / snap fastener | press stud | — |
| Separating zipper | separating zipper | open-end zip | Same part, two names |
| Invisible zipper | invisible zipper | concealed zip | — |
| Eyelet / grommet | grommet (large) / eyelet (small) | eyelet | US splits the word by hole size |
| Hook & loop | hook & loop fastener | hook & loop fastener | Velcro® is a registered trademark — write the generic term on spec sheets |
| Filling wadding | batting | wadding | The two countries use the words in opposite senses |
| Fusible interlining | fusible interfacing | fusible interlining | Both are common in the garment trade |
| Bias tape | bias tape | bias binding | — |
| Collar stay | collar stay | collar stiffener | — |
| Lab dip | lab dip | lab dip | Colour approval, step one on both sides of the Atlantic |
| Tag pin | tag pin / kimble pin | tagging gun fastener | — |
The three questions behind most RFQs
What does L mean in button sizes?
L stands for ligne, the trade unit for button diameter: 1L = 0.635 mm. A 14L button measures about 8.9 mm across — a small shirt button; 24L is about 15.2 mm — a coat button. The full conversion table is on our standards page.
How many pieces are in a gross?
One gross (G) = 144 pieces. Button MOQs are normally quoted in gross, per size and per colour — so a MOQ of 115 G at 14L means 16,560 pieces of that one size in that one colour.
What is the difference between polyester and ABS buttons?
Polyester is a thermoset: poured as a cast sheet and cut on a die, heat-tolerant, and able to carry horn, shell and pearl effects through the full thickness. ABS is a thermoplastic that takes metallic plating well, but the plating is the weak point — it can lift after industrial washing.
Button types and constructions are explained on the buttons knowledge page. Standards for tests outside our in-house scope are run by third-party laboratories and the report ships with the goods.