Choosing a lash curl is the single decision that changes an extension set most, and it is the one clients understand least. This guide explains what each lash curl on the chart actually does, which eye shapes suit which, and how curl interacts with length and thickness.
Eyelash extensions guidelines
Lash artists do not go about fixing eyelash extensions without any guidelines. The best of them usually use an eyelash extension chart as a guide when mapping various lash designs.
The major purpose of using an eyelash extensions chart is to help the artist understand the different types of lash extensions curls, thickness, length, and how each feature complements the other.
Eyelash extension curl chart
There are several eyelash extension curls on the market today. These curls aren’t one-size-fits-all, so, it is important to follow an eyelash extension curl chart to understand who can use what curl.
Under this basis, there are three types of natural lash angles, they include; straight, downward, and upward facing lash extensions.
The image above serves as a pictorial guide to the different eyelash extensions curl available.
How to choose a lash curl for your client
On selecting the ideal eyelash curl for your client, the table below will serve as a guideline to follow;
| Curl | On downward lash | On straight lash | On upward lash |
| I curl | Don’t | Yes | Don’t |
| J curl | Don’t | Lash-lift | Open-eye |
| B curl | Don’t | Lash-lift | Open-eye |
| C curl | Lash-lift | Open-eye | With care |
| D curl | Open-eye | Doll-eye | Don’t |
| U curl | Open-eye | Doll-eye | Don’t |
| M curl | Lash-lift | Wide-eye | Don’t |
| L curl | Don’t | Wide-eye | Don’t |
| L plus curl | Don’t | Wide-eye | Don’t |
The type of lash curl you decide on determines if your client will end up with a lifted (open) eye or not. The main feature responsible for the lifting eye effect is the angle of the lash curl.
Check the table below to find out which angle should be used on which eyelash extension curl to get the desired effect.
READ MORE: WHAT IS THE DIFFERENCE BETWEEN D AND C CURL.
Eyelash extension curl chart
The eyelash extensions curl chart lists the different types of eyelash extensions curl available.
The various types of eyelash extensions curl are divided into two major groups. These groups include;
Laid back lash curl
under this group, we have the L curl lashes, J curl lashes, and B curl lashes. These lash curls can also be called subtle lash curls because their effect isn’t really pronounced when compared to the other group. Subtle lash curl gives off a subtly enhancing effect to the face of the client it is used on.
- L curl lashes – L curl lashes are straightforward eyelash extensions usually without an angle. They are majorly used to enhance the feature of a natural-looking eye shape. Men clients can also use this lash curl because it merely just defines what s client already has.
- J curl lash – asides the fact that J curl eyelash extensions are the most natural-looking of this group, they also provide a lash lift effect on upward-facing lashes.
- B curl lashes – although B curl lashes are a bit curlier than J curl lashes, they are also a good option for clients with straight looking or upward facing eyelashes.
Dramatic lash curls
dramatic lash curls consist of lash extensions that go all out. As opposed to subtle lash curls, these lash curls create a noticeable effect on a client. Under this group we have the following types of lash curls;
- C curl lashes – these lash curls are very popular and they are suitable for clients who have a slight curl to their natural eyelash. Even clients with straight angled or horizontal angled lashes can use this particular type of lash curl because it will create an open eye effect.
- D curl lashes – D curl lashes are also called CC curl. D curl lashes are really curly and they need to be applied properly for them to last long. D curl lashes are the best options for clients with straight or downward angle naturally looking lashes because they will create an open-eye effect.
- U curl lashes – U curl lashes are the curliest of the set and they are the most suitable type of lash curl for clients with downward angle natural lashes to create an open eye effect.
Eyelash extensions thickness chart
To avoid poor retention of your client’s eyelash extensions, we advise you to understand the various types of lash extension sizes taking into consideration the thickness and the length of the lash set.
In so doing, the state of your client’s natural lashes is also considered because it is a critical decision that determines if the extensions will fall off prematurely.
How to choose the right lash thickness
Determining the thickness of a client’s eyelash isn’t something that should come off the head of any lash artist. In many situations, it is ok not to know the diameter of your client’s lashes. In such cases, a lash artist must compare their client’s natural lash to the thickness of lash extensions they want to apply.
Lash extensions that are manufactured and sold by companies usually come with labels indicating the thickness of each lash set.
Using this method will help the lash artist make an informed decision on the lash weight the client’s natural lash bed can carry.
In other cases, ethnicity comes into play when deciding the diameter of lash extensions to use on a client. A good example of such a scenario would be the Asians. The Asians have been known to have thinner natural eyelashes when compared to other people.
Another important factor to consider when choosing the right lash thickness for your client would be their age. As one grows old, their eyelash grows thinner with them. A client that is over 50 years old won’t have the same eyelash thickness when compared to a younger client.
Using the chart above, clients with thinner lashes should be asked to use lash extensions between the diameters of 0.10mm – 0.15mm. And clients with stronger natural lashes should opt for 0.15mm – 0.20mm.
Lash extension length guide
This guide will assist you with knowing when to apply either long or short lash extensions. Short lash extensions between 5 – 9mm are ideal for the inner corners and lashes between the lengths of 9mm – 13mm can be used for the other parts of the lash line.
This method isn’t set in stone as some lash artists have been known to mix longer lengths of lashes to get their desired result.
How to choose the right lash lengths
Just like choosing the right lash thickness, picking the right lash length is the job of the lash artist. The lash artist must understand that whatever lash length he/she decides on depends on the state of the client’s natural lashes.
For example, a lash artist should be able to tell a client that a particular lash set is too long for his/her natural lash.
Other factors to consider when choosing the right lash length includes the eyelids of your client and the type of curl in question.
In a situation where your client has hooded or droopy eyelids, it would be wise to go for slightly longer lashes. This will give off the illusion of more length as the lashes won’t hide under their eyelids.
In the case of the type of curls, lash curls such as D and U curls, the curls are more pronounced but the lash length appears shorter than they are.
Need help with lash curls? We have a detailed article on…
Reading the lash curl chart properly
Every chart uses the same lettering, running from the gentlest bend to the sharpest, and the letters themselves are more intuitive than they first appear.
J is nearly straight, adding length rather than lift. It is the most natural lash curl available and suits lashes that already curl on their own. Our J curl guide covers when it works.
B adds a modest lift while staying discreet. This lash curl is the overlooked middle option, and our B curl guide explains why it deserves more attention.
C is the most requested lash curl on any menu, visibly opening the eye without looking theatrical. Our C curl guide explains its dominance.
D is the dramatic end, designed to lift hooded and downturned eyes. Our D curl guide covers when it is genuinely needed.
Matching lash curl to eye shape
This is where a chart stops being theory. The correct lash curl depends far more on your eye shape than on how dramatic you feel.
Hooded eyes. A fold of skin covers the lash line and swallows gentle lifts, so a stronger lash curl is usually required simply to remain visible.
Downturned eyes. The outer corner droops, so a sharper lash curl at that section counteracts the angle and lifts the whole expression.
Prominent or round eyes. Already open, so a strong lash curl can look startled. Something gentler adds length without pushing the eye wider.
Almond eyes. The most flexible shape. Almost any lash curl works, so the decision comes down to preference rather than correction.
Monolid eyes. Without a crease to define the lash line, a stronger lash curl gives more visible payoff than a subtle one.
How your natural lash direction changes the choice
Eye shape is only half the picture. The direction your own lashes grow matters just as much and is routinely ignored.
If your lashes already curl upward, adding a strong lash curl on top fights that direction and produces a crimped look rather than a lifted one.
If your lashes grow straight down, a gentle lash curl simply follows them downward and the set appears to do nothing at all.
Lashes rarely grow uniformly across one eye either. Most people have lashes pointing slightly inward at the corner and outward toward the temple, which is why a single lash curl across the whole line rarely looks even.
Mixing curls across one set
Skilled technicians rarely apply one specification throughout, and mapping is what separates a designed set from a uniform one.
A frequent approach places a gentler lash curl at the inner corner, where a sharp lift looks unnatural, and moves to something stronger across the outer two-thirds.
On hooded eyes specifically, many technicians reserve the strongest lash curl for exactly the section the lid covers and use something moderate elsewhere.
Ask at your consultation whether curls will be mapped or applied uniformly. It is the most revealing question you can put to a technician about their standards.
How curl interacts with length
The two specifications are chosen separately but they affect each other, which catches out a great many first-time clients.
A sharper lash curl consumes visible length, because the extension curves back on itself. A 12mm D reads noticeably shorter than a 12mm J for exactly this reason.
Technicians often add a millimetre when working with a strong lash curl to compensate. If your set looks shorter than you expected, this is usually why.
The safe rule stays the same regardless of lash curl: no more than two or three millimetres beyond your natural lash, because weight is what causes damage.
Curl, thickness and lash health
Thickness is the third specification and the one most closely tied to whether a set is safe to wear long term.
A sharp lash curl already creates leverage on the natural lash carrying it. Pairing that with a thick fibre compounds the load considerably.
Fine natural lashes should be paired with thinner diameters regardless of which lash curl is chosen. Volume fans exist precisely so density can be built without weight.
The American Academy of Ophthalmology publishes guidance on extension safety and adhesive reactions worth reading before any first appointment.
Common mistakes when choosing
Choosing from a photograph. The same lash curl looks different on different eye shapes and lash directions.
Assuming stronger is better. A dramatic lash curl on an already-open eye looks startled rather than glamorous.
Ignoring lash direction. The most common cause of a set that technically matches the chart but looks wrong in the mirror.
Using a mechanical curler afterwards. Never. Extensions already carry their lash curl, and clamping crimps the fibre and damages the natural lash.
What to ask at your consultation
Arriving with the right questions gets you a better set than arriving with a reference photograph, because it shifts the conversation from what you want to what will work.
Start by describing the problem rather than the product. Saying that your eyes look tired, or that your lids cover your lashes, tells a technician more than naming a lash curl.
Ask which lash curl they would recommend and why. A good answer references your eye shape and the direction your lashes grow, not simply what is popular this season.
Ask whether curls and lengths will be mapped across the eye. A technician who applies one lash curl uniformly is doing less work than the job requires.
Ask what length they consider safe for your natural lashes. Someone willing to recommend shorter than you hoped is protecting your lash health rather than losing a sale.
Finally, photograph each set and note what you liked. After three or four appointments that record tells you more about which lash curl suits you than any chart can.
Changing your curl between appointments
Nothing about a first choice is permanent, and most regular clients adjust their specification over the first few sets as they learn what they prefer.
Switching lash curl usually requires a full set rather than a fill, because mixing an old curl with a new one across the same lash line looks uneven. Mention it when booking.
There is no rest period needed between changes provided your natural lashes are healthy. You can move up or down the chart at your next full set with nothing in between.
Seasonal switching is common too. Plenty of people wear a gentler lash curl through the working week and book something stronger before an event or a holiday.
Does curl affect how long a set lasts?
Retention is governed by your natural shedding cycle rather than the specification you chose, but curl does change how obvious that shedding looks.
A dramatic lash curl draws the eye to the lash line, so a single missing extension registers sooner. A gentle one blends into the natural lashes around it and hides gaps for longer.
In practice this means clients wearing a strong lash curl often book fills on a slightly tighter schedule, not because the set fails faster but because it stops looking deliberate sooner.
Aftercare matters far more than curl either way. Daily cleansing, brushing with a spoolie and keeping oil away from the lash line will do more for retention than any specification on the chart.
Book the next appointment before the shape blurs rather than after. Leaving it too long means paying for a full set again rather than a top-up, whichever lash curl you wear.
Conclusion
A lash curl chart is a starting point rather than an answer. The letters tell you how sharply each extension bends, but they cannot tell you which one suits your eyes.
Match the lash curl to your eye shape and to the direction your own lashes grow, then choose length and thickness around it rather than the other way round.
Ask whether your technician maps curls across the eye, keep the length sensible, and treat the chart as a vocabulary for the conversation rather than a menu to order from.
