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Eyelash Extension Types & Application Tips

Lash extensions are available in various materials, curls, thicknesses, lengths, and volumes. You can mix and match these qualities to customize extensions to your clients’ needs. When you consider all the possible combinations, there are hundreds, if not thousands, of lash extension types.

With so many types of extensions to choose from, it’s easy to feel overwhelmed. But don’t worry—in this guide to eyelash extension types, we’ll cover the different types of extension materials, curls, thicknesses, lengths, and volumes, their pros and cons, and how to best apply them.

Types of Materials

Lash extensions are available in various materials. The three most popular extension materials are synthetic, silk, and mink.


Synthetic lashes are manufactured from polybutylene terephthalate (PBT), which is a thermoplastic, polyester-derived material that’s heated and molded into individual lashes and fans. Synthetic extensions are thick, firm, and hard; they hold their curl remarkably well and are long-lasting. However, they tend to be on the heavier side and can damage natural lashes if worn for extended periods of time.


Silk is a bit of a misnomer as these extensions are rarely made from genuine silk. Rather, they’re made from PBT—the same material used for synthetic extensions.

Real silk extensions are fluffy, soft, and have a shiny semi-gloss finish. They’re very pretty, but this prettiness comes with a price. A full set of silk extensions costs $500, on average. Genuine silk extensions are also non-vegan since the silk comes from farm-raised silkworms. Farmers kill these silkworms during the pupal stage so they can extract silk from the cocoons.

Faux silk extensions look very similar to natural lashes; they’re soft, fine, flexible, and have a lovely sheen. They’re also lightweight, which makes them a fantastic option for clients with weak or thin natural lashes that can’t support heavier materials.


Mink extensions are another misnomer. Nowadays, salons rarely use genuine mink lashes because they don’t want to promote animal cruelty. Genuine mink fur is forcefully harvested from minks raised on unsanitary fur farms. Fortunately, there’s a PBT alternative for this lash material as well.

Real mink lashes are feathery, silky, and durable, and like real silk lashes, they’re non-vegan and costly. Faux mink lashes have a dark, rich color that looks like natural lashes covered in a coat of black mascara. They’re thick, soft, and bendable.

Types of Curls

With lash extensions, there is a nice assortment of curls to choose from. The curl is the angle at which the extensions curve. There are dozens of curl types, but the most commonly used styles are J, B, C, D, and L, with J curls being the most subtle and natural and L being the most dramatic of the bunch.

J Curls

J curls closely mimic the natural lash shape, with a flat base and a slight curvature at the tip. They work well on clients with straight or upward-pointing lashes. However, you should avoid using them on clients with downward-pointing lashes; on these individuals, they can make the eyes look small and heavy-lidded.

B Curls

B curls have slightly more curl to them than J curls. They’re ideal for use on the inner corner lashes to create a soft, subtle effect.

C Curls

C curls are the most popular curl option. They provide a prominent lift and curl without looking unnatural or extreme. They work well on almost any type of client, no matter their natural eye shape or lash pattern.

D Curls

D curls provide a dramatic, lifted look that opens up the eyes and makes them appear more youthful. This is one of the best curls for clients with downward-pointing lashes, as it creates an attractive doll-eyed look.

L Curls

L curls feature a sharp curve that forms an “L” shape. They’re ideal for creating cat-eyed looks with heavily upturned outer eye corners.

Types of Thicknesses

You can also customize the thickness of the extensions. Thicknesses range from 0.03 mm to 0.25 mm; 0.15 mm is the preferred thickness for a classic, natural look. For clients with extra-fine natural lashes, a cosmetologist or esthetician may use 0.10 mm extensions instead.

Thicknesses between 0.10 mm and 0.15 mm are the most commonly used. 0.20 mm and 0.25 mm extensions are too heavy for most people’s lashes, while 0.03 mm and 0.05 mm extensions are incredibly thin and look unusual unless paired with substantial volume.

Types of Lengths

You can separate lash extensions into four lengths: short, medium, long, and very long. Short extensions are sets with lashes less than 8 mm long. Medium extensions feature lashes measuring between 10 and 12 mm long. Long extensions have 13 to 14 mm lashes, and extensions with lashes more than 15 mm are very long.

Types of Volumes

Volume refers to the number of lashes per extension fan. 1D extensions, also known as classic extensions, have one lash per fan and provide an understated look. 3D to 6D extensions provide a bit of extra volume. 10D to 15D extensions are distinctive and exaggerated—the wearer will look like they have several thick coats of mascara on.

Types of Styles & How To Apply Them

The extension style your client wants has the biggest impact on the application process. Here are four trendy eyelash extension styles—cat eye, doll, natural, and squirrel—and how to properly apply them:

Cat Eye

The cat eye style features long, prominent lashes near the outer corners of the eyes. To achieve a cat eye look, apply short lashes to the inner corner of the eye, steadily increasing the length of the lashes as you near the outer corner of the eye.


This style opens up the eyes for a cute, youthful look. To create doll eye extensions, apply shorter lashes (8 to 10 mm) near the inner and outer corners of the eyes and longer lashes (12 mm or longer) to the middle.


As the name suggests, this style resembles natural lashes. The length of the lashes remains relatively consistent throughout, with 11mm lashes near the center and slightly shorter (8 to 9 mm) lashes in the corners.


To create a squirrel eye look that lifts and opens the eyes, place long lashes (11 to 12 mm) under the arch of the eyebrow and shorter lashes everywhere else.

At Lash and Beauty Store, we carry high-quality Borboleta extensions you can use to craft your clients’ dream lashes. Whether they want long lashes, short lashes, colorful or natural, cat eye or doll, we have professional lashes you can use for a variety of unique, personality-filled looks.

Eyelash Extension Types & Application Tips