How to apply lash extensions for the best retention

When you extend natural lashes more than it’s healthy for them, they will shed quicker because they cannot handle the excess weight. Unfortunately, this will cause loss or retention and damage the customer’s natural lashes, so over-extending should be avoided at all costs!

How can I recognize that lash extensions are too long and will cause damage?


When too much volume is added, the natural lash will bend down. This is recognizable from the front and side view when the customer’s eyes are open. Therefore, after finishing the lash application, it’s essential to check that NO lashes have bent lower than the rest of the line. If you notice any, removing the extension and replacing them with shorter or lower volume extensions is important.


When you notice that your customers’ lashes are becoming weaker after they start wearing extensions, it’s a good idea to double-check that you are not using too much volume or lashes that are too long.


If you have customers with long extensions and notice that they are not getting good retention and everything else seems to be on point, try shorter extensions to see if that improves their retention.

How much is it safe to extend?

Everything comes down to the strength and length of the natural lash and the weight of the extension—the longer and thicker the natural lash, the more weight it can hold.


The diameter and length of the extension determine how much it weighs. For example, the following extensions with different diameters have roughly the same weight:

lash fans

The general rules for extending are:


Classic lashes – natural lashes can be extended up to 30% of their length. If the natural lash is 10mm, it may be extended by 10mm x 30% = 3mm. So the longest extension you could use on this lash would be 10mm + 3mm = 13mm.


Volume lashes – due to their smaller weight and the possibility of wrapping them around the natural lash, volume lashes may be extended by 40% of the length of the natural lash. So a 10mm natural lash could hold up to 14mm extension.


It’s essential to remember that these are the maximum lengths, not that all lashes should be extended that much.


The longer the extensions you add, the fluffier they look. So if you want to create a dense dark lashline, it’s better to go with shorter lengths. In fact, shorter extensions have better retention, and extensions that are often shorter than natural lashes are used.


Watch this LIVE Ruthie did with Maria from @bling_therapy_pro about how to improve retention by choosing the right volume for lashes:

How far from the skin should extensions be applied?


Lashes should always be applied very close to the lash line without touching the skin to avoid causing damage. Recommended distance from the eyelid is 0.5mm for classic lashes and 0.3mm for volume lashes. Classic lashes should be applied further because they are thicker and cannot be wrapped around the natural lash, so they feel more irritating against the skin when customers touch their lashes.

lash extension

At which angle should extensions be applied for best retention?

The base of the extension should always touch the natural lash first. The point of contact between the natural lash and the extension should be as long as possible for maximum retention (this is important to remember also when choosing the extension curls for the customer).

applying lash extensions

Sometimes customers have crooked eyelashes that are difficult to extend. If that happens, ignore the direction of the eyelash tip and focus on the base. If the base is straight, you can still get good retention. However, if the base is crooked, glue the extension only on the straight part. This means that you will not get the same long contact point between the extension and the natural lash, so retention will not be as good, but at least the direction of the extension will be on point, and there will not be a gap in the lash line.


When the base of the extension is lifting (detached) from the natural lash, it causes an uncomfortable poking sensation to your customer, in addition to providing bad retention.

applying lash extensions

Lash adhesive polymerizes when extensions touch the natural lash, so try not to move it afterward. In the past, it was recommended to slide the extensions on the natural lash to cover the natural lash with glue, but nowadays, lash adhesives cure so fast that doing so will have a terrible impact on retention. This is also why you should NEVER wipe off excess glue on the eye pad – it interferes with the polymerization process and will result in loss of retention.


Here’s how to control the glue you pick up without compromising retention: Which glue pick-up method creates the best retention?

Should lashes be applied from the natural lash's top, bottom, or side?


To create the densest, most even lash line and maximum retention, I recommend the following:

  • The top layer of lashes – apply extensions from underneath
  • Middle layers – apply extensions however you like
  • Bottom layer – apply extensions from the top
applying lash extensions

This makes a difference in retention because when customers brush or touch their lashes, the brush creates mechanical damage. It may seem as if the damage is so minimal that it doesn’t impact retention, but it’s essential to bear in mind that we work with the smallest amount of cyanoacrylate, so even all the small things matter!


If you have a natural lash between the brush and the extensions, it will offer some protection to the extensions.


This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.

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