Lash Extensions Thickness Guide: Understanding the Look & Feel

Lash extension thickness, commonly known in the lash industry as ‘diameter’, is one of the most important factors in keeping your client’s natural lashes healthy. The right thickness can enhance your guest’s eyes with a natural effect or a bold, dramatic finish. But beyond aesthetics, lash thickness also affects the weight of extensions, lash comfort, and long-term lash health.

Understanding lash extension thickness will help you customize each set based on your guest’s lash health, lifestyle, and style preferences. Let’s break down the different thickness options and how to choose the right one.

What is Lash Extension Thickness?

Lash extension thickness, or diameter, is measured in millimeters (mm), typically ranging from ultra-fine .02mm volume lashes to thick, .25mm classic lashes. The thickness you choose impacts the weight of the lash extension, the overall look, and how it blends with natural lashes.

Selecting the right diameter for each client is crucial to guest satisfaction—not just for the look and feel but also for maintaining healthy, long-lasting lashes. Using extensions that are too heavy for a guest’s natural lashes can lead to premature shedding or damage.

Lash Diameter Breakdown: Look & Feel

1. Ultra-Fine Lashes (.02mm-.07mm)

.02mm & .03mm Cashmere Touch Lash Extensions 

Look: Feathery and weightless yet can be styled to have a dense look. Perfect for creating mega-volume sets or, popularly known as ‘Angel Sets’.
Feel: Offers a cashmere touch of softness, providing the most comfortable wear.
Best For: Mega volume or adding bundles for texture. A very versatile diameter that can create a dense, full mega volume set OR a natural feathery Angel Set with bundles. 

.05mm, .06mm, & .07mm Lash Extensions 

Look: Traditional volume—ranging from a lighter volume with a .05mm diameter to a standard volume weight of 0.07mm. Creates full, fluffy sets with soft texture.
Feel: Lightweight and flexible. Depending on the diameter, 3-9 extensions per natural lash can be used without damage to the natural lash.
Best For: Volume and texture techniques. Use a .05mm for clients with fine natural lashes. 

2. Medium-Thin Lashes (.10mm - .12mm)

Look: Used with a 1:1 placement ratio, these diameters offer a subtle, natural enhancement. These lashes add noticeable length and definition while remaining soft and natural-looking.
Feel: Light and comfortable
Best For: Classic lashes for guests with brittle or finer natural lashes. 

3. Standard Classic Lashes (.15mm - .18mm)

Look: The .15mm diameter is the go-to thickness for classic lash sets—enhancing length and definition while maintaining a natural look.
Feel: Noticeable but still comfortable. Provides a mascara-like effect without feeling too heavy.
Best For: Classic sets and guests with medium to strong natural lashes who want a soft yet textured look.

4. Special Occasion Lashes (.20mm - .25mm)

Look: Bold, dark, and ultra-dramatic. Creates a thicker lash effect with a dense lash line.
Feel: Heavier on the natural lash, with a more prominent presence. Some guests may feel the difference in weight.
Best For: Guests with strong, healthy lashes. This diameter is Ideal for one-off special occasions, rather than everyday wear. If worn continuously, damage can occur to the natural lash. 

How to Choose the Right Lash Thickness

Match the lash thickness to the client’s natural lash health – Our number one job as lash artists is keeping our guests’ natural lashes as healthy as possible. We always say “Healthy lashes are happy lashes”. So, we recommend matching the thickness of the natural lashes to the thickness of the lash extension used. The stronger the natural lash, the heavier the extension the artist can use. If your guest has ultra-fine, delicate lashes, choosing extensions with a diameter ranging from .02 mm to .07 mm is the safest choice. If they have stronger lashes, they can support thicker extensions and larger handmade volume fans.

 

Consider the desired style – As lash extensions are ever customizable, there isn't one rule of thumb for each lash thickness as it does depend on the client's lash health and desired look. For a soft, natural style, use a classic diameter ranging from .10mm to .15mm. For a more bold, voluminous look, go with volume diameters ranging from .02mm to .07mm. If you have creative freedom for a photo shoot or wedding, use .18mm-.25mm as thicker diameters and longer lengths pick up beautifully on camera, but never for everyday continuous wear. 

Lifestyle & comfort – Guests’ who prefer a lightweight feel, use .02mm/.03mm bundles or a classic lash with a .10mm/.12mm diameter. Those who love a dramatic look can request volume fans using a diameter of .02mm to .07mm.

Common Mistakes When Selecting Lash Thickness

Using too thick of extensions on weak or brittle natural lashes – This can lead to premature shedding or damage to the natural lash. Always assess the guest’s natural lash strength during the consultation before choosing the correct thickness.

Choosing thickness based on trends instead of client needs – Just because a trend favors drama or length, doesn’t mean it’s the right fit for every guest. Customization and lash health is key!

Overlooking comfort and maintenance – To maintain lash extensions, proper lash care, and regularly scheduled fill appointments are a must! Encourage each client to protect their investment by washing their lashes daily using Borboleta’s Lash Bath and Clean Swoop Brush. This will help keep the lash line healthy and comfortable and their natural lashes shed through the lash growth cycles in between fill appointments. 

Shop BorboletaPro for Quality Lash Extensions

Choosing the right lash diameter makes all the difference in creating healthy and long-lasting lash sets. At BorboletaPro, we offer premium lash extensions in a range of thicknesses to help your creativity create customized lash sets, every time!

✨ Shop our collection now and give your clients the perfect lashes they’ll be obsessed with! ✨