Tips to Choosing the Right Lash Extension Length

Does the length of extension make or break your look? Can long extensions really damage the natural lashes?

The answer is YES! So that's why understanding how to choose the correct length of lashes for your client is so important.

As a lash artist, it's necessary to know what extensions are suitable for your clients' lashes. Lay out expectations and be forthcoming with your clients so that they know that you have their best interest in mind when choosing appropriate lengths and weights for their lashes. Here are 5 tips to help you choose the correct lashes for each client.




Carry multiple diameters, curls, and lengths in your lash arsenal so that you can customize your client's lashes while simultaneously setting them up for a long-term lash relationship. Applying lashes that are too long or too heavy can cause long-term damage and prevent the lash follicles from producing healthy lashes. If you used the same lashes on a client with thin, fine natural lashes that you do on a client with thick, coarse naturals, one of those clients is getting a disservice. Similarly, a client with 5mm natural lashes vs. a client with 11mm natural lashes, should not both be carrying 13mm extensions on their eyes. 

Using the Size Matters isolation tweezer helps me when I need to explain to my clients where their NL measures up and what that means for lash expectations, especially if a previous artist has placed extensions on them in the past that were too long or heavy. The Size Matters tweezer has a ruler along the edge of the backside to show you how long the natural lash measures up!




Determine whether your client prefers length or fullness. I love to use the example of flowers in a vase. When flower stems are long, they stick out of the mouth of the vase, and there is a lot of space in between each flower, so they look more sparse. But, when you cut the stems, the gaps disappear, and the flowers bunch up closer together making the same amount of flowers look fuller. Lashes work the same way. The longer the extensions, the more sparse they can potentially look. The closer we stay to a client's natural lash length will make the lash line appear fuller. If your client prefers fullness, explain that to create fullness, especially with classic lash application, since we are limited to the number of natural lashes they have, we must use shorter lashes.




If you're going to go up in length, consider choosing to going down in diameter. A thinner extension will make up for the added length by reducing the weight. This is when knowing advanced volume techniques will come in handy as you can make fans with smaller diameter lashes that can be used to create various looks. Keep in mind, when using lashes that are longer than 3mm past the natural lash, you run the risk of twisting and breaking the natural lash as it grows out. Make sure those length-loving babes are in at least every two weeks for their fills to replace grown-out extensions with new extensions at the base of the natural lash before they grow out too long.




Playing around with curls can look like you are adding length but in reality, you are just using a tighter curl. When a client says that they want to have longer lashes, ask more questions to find out what they're really after. If they say that they feel like you can't see their lashes when they look straight on, what they really need is a tighter curl that shows more from the front. 

When talking curls, make sure that you analyze the curl of the client's NL. Do your client's NLs point downward, sit neutral, or perk upward? The curl you choose can affect the overall look. If your client has downward facing lashes, try blending B curl and C curls to give the lashes a lift without having such a dramatic difference between the NLs and extensions. If your client's lashes perk upward, they already have enough lift that a C curl extension can look like a D curl. Avoid starting out with D curl, as it can look TOO curly on them. If they decide they want a bit perkier later, try using a CC curl or D curl.




Always follow the 3mm rule. You've heard it's better to be safe than sorry and the same applies to lash application. Long lash extensions can cause permanent damage to the hair follicle that results in shorter, weaker lashes and the repetitive damage could kill the follicle entirely. That's why I always recommend the 3mm rule, which we teach in the Lash Affair Academy. The 3mm rules states for the health of the client's natural lash, you should never place an extension that is longer than 3mm past the length of the natural. Using the Size Matters tweezer to map out your client's NL line will give you the exact lengths you need to follow this rule and ensure that you are using safe lengths every time. 

As you can see, there is a lot to think about when choosing what extension style is right for your client. To get more in depth on this topic and learn other necessities to lash extension application, consider taking a classic or volume training from Lash Affair Academy

We host trainings all over the country and can even come to you if there isn't a location close to you. Email me at for more info on upcoming classes. 



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