Author: LASHMAITRE Product Education Team

Topic: Technical Artistry & Product Knowledge

Reading Time: 25 Minutes

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Introduction

In the architectural world of lash artistry, length creates visibility, but curl creates personality. Understanding the different curls of eyelash extensions is the single most critical skill for a master technician. A client’s final look—whether they appear wide-awake, sultry, or natural—depends entirely on the angle at which the extension lifts from the eyelid.

For salon owners and B2B wholesalers in 2026, the market has evolved beyond the basic “C and D” inventory. Clients now demand bespoke corrections for hooded eyes, downward-pointing lashes, and asymmetry. Stocking a comprehensive range of different curls of eyelash extensions is no longer optional; it is a competitive necessity.

This comprehensive guide will decode the entire alphabet of curls. We will provide a definitive eyelash extension curl chart, analyze the classic C curl vs D curl debate, and explore how specialty options like L curl lashes for hooded eyes are revolutionizing the industry.

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The Science of Shape: Understanding PBT Thermal Setting

Before we classify the curls, we must understand how they are made. High-quality different curls of eyelash extensions are manufactured from PBT (Polybutylene Terephthalate).

The Heat-Setting Process

PBT is a thermoplastic engineering polymer.

1. Rolling: Raw fibers are rolled tightly onto metal rods of varying diameters.
2. Heating: The rods are heated to high temperatures (approx 100°C – 150°C) to alter the fiber’s memory.
3. Cooling: Rapid cooling locks the shape in place.

Scientific Context: According to Wikipedia’s entry on PBT, this material is chosen for lash extensions because of its excellent resistance to creep (deformation under stress) and heat aging. This means a high-quality lash won’t lose its curl in a hot shower.

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The Definitive Eyelash Extension Curl Chart

To navigate the market, you need a map. This is the industry-standard eyelash extension curl chart used by top academies.

The Master Curl Matrix

Use this table to train your staff on curl identification.

Curl Name	Angle (Approx.)	Description	Best For	Effect
J Curl	30°	Slightest lift	Straight lashes / Men	No-makeup look
B Curl	45°	Soft, natural curve	Inner corners	Subtle definition
C Curl	60°	Standard Lift	Almond Eyes	Mascara Effect
CC Curl	65°	Hybrid C/D	All Shapes	Textured Lift
D Curl	70°	Dramatic Lift	Downward lashes	Open Eye / Drama
U (DD) Curl	80°+	Extreme curve	Doll Eye maps	Theatrical
L Curl	90° (Flat Base)	Sharp vertical lift	Hooded / Monolid	Eyeliner Effect
M Curl	Lifted Base	Soft vertical lift	Deep Set Eyes	Sharp Lift

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The Showdown: C Curl vs D Curl

The two most common different curls of eyelash extensions sold globally are C and D. Understanding C curl vs D curl is vital for inventory management.

C Curl: The Universal Standard

• Profile: Mimics a natural lash that has been curled with a mechanical curler.
• Usage: 50% of global inventory. It fits almost everyone.

D Curl: The Modern Favorite

• Profile: A semi-circle shape. It provides the most visibility from the front view.
• Usage: Essential for clients with straight or downward-growing natural lashes. If you put a C curl on downward lashes, it will look straight. D curl lifts them up.

When to Choose Which?

• Choose C Curl If:
  • The client has deep-set eyes (D might hit the eyelid).
  • The client wants a “natural but better” look.
  • The client has naturally curly lashes (D might curl back into the skin).
• Choose D Curl If:
  • The client wears glasses (D curls up away from the lens).
  • The client has hooded eyelids (needs to clear the hood).
  • The client wants a “Strip Lash” look.

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Problem Solvers: L Curl Lashes for Hooded Eyes

One of the biggest innovations in different curls of eyelash extensions is the development of the “Flat Base” curls (L, L+, M). These are specifically designed for L curl lashes for hooded eyes.

The Anatomy of a Hooded Eye

Clients with hooded eyes or Ptosis (drooping eyelid) have extra skin that sits over the lash line.

• The Problem: A standard C or D curl curves immediately. On a hooded eye, the curve hits the eyelid skin, pushing the extension down or causing irritation.
• The Solution (L Curl): It has a long, flat base (like the letter L) and then shoots straight up. This allows the lash to extend out from under the hood before lifting up.

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Design Logic: Best Lash Curl for Eye Shape

A master artist maps the different curls of eyelash extensions to correct the client’s facial features. This is facial geometry.

Eye Shape & Curl Matching Protocol

Eye Shape	Characteristics	Best Lash Curl	Avoid	Why?
Almond	Balanced proportions	C or CC Curl	None	Most versatile shape.
Deep Set	Brow bone protrudes	L, M, or D+	J or B	Need extreme lift to be seen from under the brow.
Protruding	Bulging / Round	B or C Curl	D or DD	D curl makes round eyes look “startled” or too round.
Monolid	No crease	L or L+ Curl	C Curl	L curl sits flush on the straight lash line.
Downturned	Outer corners drop	D Curl (Outer)	B Curl	D curl lifts the sad/droopy outer corner.

Market Data: According to Grand View Research, the demand for “specialty curls” (L, M) grew by 18% in 2025, driven by the Asian and aging demographic markets.

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Advanced Artistry: Mixing Lash Curls

You do not have to use one curl for the whole eye. Mixing lash curls is the secret to a bespoke set.

The “Lift and Elongate” Technique

Using different curls of eyelash extensions in zones can alter the eye shape dynamically.

How to Mix Curls

1. Inner Corners (B/C Curl): Natural lashes here are short and straight. Use a softer curl to prevent them from hitting the nose bridge.
2. Center (D/CC Curl): Use a stronger curl to open the eye vertically (Doll Eye effect).
3. Outer Corners (B/C Curl): Transition back to a softer curl to elongate the eye into a Cat Eye.
   • Warning: Using a D curl on the very last outer lash often looks messy and droopy. A B curl gives a “swoop” effect.

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The Physics of Retention: Curl Impact on Bonding

Believe it or not, the curl affects how long the lashes last. This is simple physics: Surface Area.

The Bond Interface

Retention relies on the contact area between the natural lash and the extension.

• Match: Placing a straight extension (J/B) on a straight natural lash = High Contact = Great Retention.
• Mismatch: Placing a curvy extension (D) on a straight natural lash = Low Contact (only the very base touches).

Retention Risk Assessment

Natural Lash Shape	Extension Curl Used	Contact Area	Retention Forecast
Straight	L / M Curl	Maximum (Flat Base)	Excellent (5-6 Weeks)
Straight	C Curl	Medium	Good (4 Weeks)
Straight	D Curl	Minimal (Point Contact)	Risk (2-3 Weeks)
Curled	D Curl	High	Excellent
Curled	J Curl	Low (Gap at base)	Poor

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Sourcing Strategy: Manufacturing Consistency

For B2B buyers stocking different curls of eyelash extensions, quality control is paramount. Nothing frustrates a lash artist more than a “D Curl” tray that looks like a “C Curl.”

The “Heat Resistance” Test

Cheap PBT fibers lose their curl when exposed to heat (hot showers, blow dryers, steaming).

• LASHMAITRE Standard: Our fibers undergo a proprietary “Double-Heat Lock” process. We test our curls by submerging them in 100°C water. They maintain 99% of their shape.

Wholesale Quality Checklist

• Consistency: Is the curl identical from line 1 to line 12?
• Labeling: Is the curl labeled on the strip (e.g., “0.07 D”)? This helps artists when they mix palettes.
• Foil Backing: Does the strip peel off the palette without leaving paper residue?
• Material: Is it 100% Korean PBT? (Avoid Chinese acrylics which look shiny/plastic).

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Conclusion: Curl is the New Color

In the past, lash artists focused on thickness. In 2026, they focus on curl. Mastering the different curls of eyelash extensions allows you to be an architect of the face.

Whether you are correcting a hooded eye with an L curl, creating drama with a D curl, or ensuring longevity by matching the curl to the natural lash, your inventory choices define your success.

LASHMAITRE provides the world’s most consistent, heat-resistant, and extensive curl library. From B to M, we have the angle for every eye.

Ready to expand your artistry?

Stock the curls that master artists trust.

Register for a Wholesale Account & Download Curl Chart

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People Also Ask (FAQ)

Q: What is the most popular eyelash extension curl?

A: Globally, the C Curl is the most popular of the different curls of eyelash extensions. It offers a “sweet spot” of lift—noticeable enough to look like makeup, but natural enough to suit 90% of eye shapes. However, the D Curl is a close second, especially preferred by younger clients wanting a more dramatic, “open-eye” look.

Q: How do I know which lash curl to use?

A: To find the best lash curl for eye shape, look at the client’s natural lashes and eyelid.

1. Straight/Downward Lashes: Use D, L, or M curl to provide lift.
2. Hooded Eyes: Use L or L+ curl to clear the eyelid skin.
3. Protruding/Round Eyes: Use B or C curl to elongate rather than widen.
4. Deep Set Eyes: Use D or CC curl to make the lashes visible from under the brow bone.

Q: Can you mix different curls of eyelash extensions?

A: Yes, mixing lash curls is a sign of an advanced lash artist. A common map is to use C curls in the inner corners (for comfort), D curls in the center (for lift), and B or C curls on the outer corners (for elongation). This creates a textured, multidimensional look that mimics the natural variation of real eyelashes.

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References & Further Reading

1. Wikipedia. Polybutylene terephthalate (PBT) Properties.
2. American Academy of Ophthalmology (AAO). Ptosis (Drooping Eyelid) Anatomy.
3. Grand View Research. False Eyelashes Market Size, Share & Trends Analysis.
4. LASHMAITRE Academy. “Advanced Curl Mapping Guide 2026.”

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📅 Content Administration

• Last Updated: January 16, 2026
• Changelog:
  • v1.0: Initial publication. Content focuses on PBT chemistry and Angle Definitions.
  • v1.1: Added “L Curl for Hooded Eyes” section and “Retention Physics” table.
• Next Review Date: July 16, 2026