Learn how to read an eyelash spec sheet — curl types, thickness, length, D-count and materials explained for brands ordering wholesale or private label lashes.
Every lash order runs on a spec sheet, but most brand founders read only the style name and price. That is how you end up with "CC curl" that behaves like a D, "0.07 thickness" that photographs like 0.15, and volume lashes whose D-count does not match what you ordered. This guide explains every field on a professional lash spec sheet, what questions to ask your factory about each one, how the same style name can hide very different products, and how to write specs that survive production, reorders and multi-year brand building.
If you have ever wondered why two suppliers' "wispy clusters" feel completely different, the answer is always in the spec. Learning to read and write these fields is the single most valuable skill for a lash brand founder.
Curl describes how sharply the fiber bends away from the band:
Ask your factory: for curl angle tolerance (in degrees if they measure it), and for a photo of the actual style from the side, not a catalog illustration. Curl perception also depends on length (longer fibers look curlier) and band angle, so specify curl and length together, never in isolation.
Length is measured in millimeters. Common ranges: 7–15 mm for clusters, 8–16 mm for strips; extension trays often 9–16 mm. But length alone is not the story:
Thickness describes fiber size, but the measurement system depends on the product category, so do not treat extension, strip and cluster specs as directly interchangeable:
Ask your factory: to state the measured diameter (or denier, with the conversion basis) and the agreed tolerance in writing; different materials, grades and processes use different tolerance windows, so treat any specific figure as something to confirm per SKU rather than an industry universal. Also confirm fiber material (PBT is a common premium synthetic; silk-look and HD/matte variants differ in finish chemistry). See what fake lashes are made of for material background.
The "3D / 5D / 6D / 10D / 14D" in a style name usually refers to the number of fibers per fan or cluster, but the exact definition varies by product structure and supplier labeling. Some factories count fibers per fan; others use the D-label as a marketing tier. Treat it as a starting point, not a universal standard:
D-count interacts with fiber thickness and fan width: ten fine fibers weigh less than ten thick ones, and a wide fan covers more lid than a narrow one at the same D-count. Full differences are explained in 3D vs 5D vs 10D explained; but on a spec sheet, always pin D-count together with thickness, fan width, and the factory's own definition of what "D" means for that product, so your factory cannot quietly change either. "6D at 0.07, fan width 8–10 mm" is a spec; "6D wispy" is a mood. Orders should be governed by the approved sample and the written spec.
Pairs or sets per tray/box, tray type, box structure, insert cards: all belong on the spec so production matches your approved sample. Count errors ("56 clusters" printed on a tray holding 50) are among the most common and most preventable packaging defects. See the packaging guide for options and the proofing process.
| Field | Example |
|---|---|
| Style name | Wispy Spike Cluster — "Aria" |
| Curl | CC (photo-approved, angle ref attached, ±3° tolerance) |
| Length pattern | 10-12-14 mm spiky map (spikes 14, base 10) |
| Fiber thickness | 0.07 mm PBT, matte finish, agreed tolerance per PO |
| Cluster count | 6D per cluster, fan width 8–10 mm |
| Band | Knot-free, clear base, color ref #CLR-A |
| Count | 56 clusters per tray |
| Packaging | Printed tray + branded sleeve, SKU "AR-01", box v2.1 |
One row like this, attached to every PO with the golden-sample photo set, eliminates most quality disputes before they happen (see keeping manufacturer quality consistent).
Not perfectly. "CC" at one factory can be slightly different at another, sometimes by several degrees. Always approve samples per factory and keep factory-specific golden samples; never assume cross-factory curl equivalence in your listings.
For DIY clusters, 0.07–0.10 with C or CC curl covers most consumer demand. For extensions, 0.07 C/CC is the professional default, then expand from sell-through data, not from catalog browsing.
Measure against samples: calipers for thickness, a curl gauge or side-by-side photo against a known reference for curl, a ruler for length maps. Inconsistencies between spec and sample are a serious red flag; the spec sheet is a promise, and promises that fail before production will fail after it.
Yes: even simpler, but still present. Without a written spec, your reorder is a memory game, and memory does not survive staff changes or factory line changes.
One person. Shared spec ownership without version control produces conflicting POs. Assign an owner (often the founder in year one), keep files version-dated, and route all changes through them.
Order from suppliers who speak specs. JINYANHUA ships every private label and wholesale order with complete, photo-backed spec sheets, and can build specs from your references. Browse the catalog or request a spec-matched quote.
