Every term a UK lash tech actually needs to know. Plain English, no filler. Bookmark this page, we'll keep it updated as new techniques and products come in.
Lashing is technical work. The training course throws 40 terms at you in two days, the Instagram tutorials assume you already know what they mean, and the glossary you need sits across 15 different websites. Here's the lot, in one place, explained by someone who actually uses them in a studio.
Curl types
The curl is the shape of the lash extension. Natural lashes have different natural lifts, so the curl you pick needs to match (or enhance) what the client already has.
J curl
Almost no curl. Looks like a natural lash extended slightly. Used on hooded eyes or clients who want the most natural finish possible. Rarely used in UK lash work now because most clients want more visible lift.
B curl
Slightly more lift than J. Still very subtle. Good for mature clients or those who've never had lashes before and want to ease in.
C curl
The industry workhorse. Clean lift without dramatic curl. Works on most eye shapes. If you're asking "which curl should I pick", the safe answer is C curl for natural, D curl for dramatic.
CC curl
Between C and D. More lift than C but not as dramatic as D. Used when C is flat and D is too fluffy.
D curl
Dramatic curl. Almost a fluttery look. The go-to for Russian volume and fox/doll/cat eye mapping. Most volume techs stock D curl as their core SKU. Full curl guide here.
DD curl
Even more lift than D. Rarely needed. Some techs keep a tray for clients with very straight natural lashes who can't hold any less curl.
L curl
Flat at the base, sharp lift at the tip. Looks like the letter L tipped forward. Used on hooded and monolid eyes where a standard curl disappears under the lid. A lifesaver for these eye shapes.
L+ curl (also LC, LD)
L-shape base with a softer curl at the tip. Gives lift without the sharpness. Good for hooded eyes where you want the lift but not the spikiness.
M curl
Newer curl. Flat base, then curl, then flat tip. Holds lift better on clients who wear glasses or sleep face-down.
U curl
Very dramatic. Almost a full semi-circle. Editorial-style sets, photoshoot work, clients who want the fluffiest look possible.
Set styles
Classic set
One extension per natural lash. The most anatomy-respecting style. Adds length and definition without volume. Entry point for most new techs.
Russian volume, also called Volume set
Multiple thin extensions fanned onto one natural lash. Creates density and a fuller look. Fans are made by hand or picked pre-made. The bread-and-butter of experienced techs in the UK.
Hybrid set
Mix of classic and volume. Usually 50/50 or 70/30. Gives definition from the classics plus density from the fans. Most common set request in the UK right now.
Wispy set
Classic or hybrid with deliberately spaced-out longer lengths. Creates a fluttery, piecey look. Influencer-driven trend that's still going strong.
Spikes
Groups of 2-5 lashes clustered tight and dipped in glue so they form a spike. Placed between fans for edgy editorial sets. A Wispy set often uses spikes.
Mega volume
Very thin (0.03 or 0.05) fans with 10-20+ lashes per fan. Creates extreme density. Technically advanced, time-consuming, not every tech should be selling this.
Kim K set or Natural set
Client language for "make it look like Kim K's lashes" or "I just want them natural". Translate into the tech language: usually hybrid, C or D curl, natural length profile (8-12mm typically).
Fox, doll, cat, squirrel mapping
Different length distributions across the eye. Fox = longer toward outer corner. Doll = longest in the middle. Cat = slight flick at the outer edge. Squirrel = length concentrated slightly inwards from outer corner. Mapping is how you draw the length pattern onto the undereye gel pad before you start.
Thickness (diameter)
Measured in millimetres. Thinner fibres = more fans per client = volume work. Thicker fibres = classic work.
0.03mm
Thinnest standard diameter. Used for mega volume and fluffy volume sets. Very light on the natural lash. Hardest to pick cleanly with tweezers.
0.05mm
Standard Russian volume diameter. Fans pick cleaner than 0.03. Most UK volume techs stock this as their main tray alongside 0.03.
0.07mm
Volume-to-hybrid middle ground. Used in 3D-5D fans or as singles in hybrid sets.
0.10mm
Thick volume or thin classic. Used for 2D-3D fans or as a single for a denser classic look.
0.15mm
Standard classic diameter. Every classic tech carries this. Gives definition without being heavy.
0.18mm and 0.20mm
Thick classic. For clients with very strong natural lashes or for an extra-bold classic look. Use carefully, too thick for weak natural lashes.
Lengths
Measured in millimetres, usually 7mm to 16mm. Most UK work uses 8-14mm. Check the client's natural lash length and go no more than 30-40% beyond it to keep the extension healthy.
Tray types
Single length tray
All rows the same length. Gives you a precise block of 12mm (or whatever). Used when you're mapping a specific pattern.
Mixed length tray
Multiple lengths on one tray, usually 8mm to 14mm. Faster for full sets because you don't need to switch trays. 90% of working techs use mixed length for most appointments.
Pre-made fan tray
Fans already made and placed on the tray. Grab, dip, place. Much faster than hand-fanning. Quality varies hugely between brands.
EasyFan or Promade tray
Fans that "open" as you lift them off the tray. A hybrid between pre-made and hand-fanning. Very fast application. Check our EasyFan range.
Angel lashes
Two-tone trays (usually tips coloured or highlighted) for a subtle editorial finish.
YY lashes
Pre-made Y-shaped fans. Two lashes joined at the base. Creates a wispy look fast.
Wet Look lashes
Finished with a glossy coating. Gives that "mascara-coated" finish without actual mascara. Popular with clients who want definition.
Products and workflow
Primer (Pre-Treatment)
A liquid that cleans and pH-balances the natural lash before glue application. Removes oil, residue, and anything the cleanse missed. Skip this and your retention caps at 50-60%. Shop our Pre-Treatment Primer.
Cleanser (Lash Shampoo)
Gentle foaming wash used before the appointment starts. Cleans makeup, oil, and debris off the client's lashes and lid. Shop our Lash Shampoo.
Gel remover
Thicker, gel-based glue remover. Used for full removals. Stays put on the lashes without running into the eye.
Cream remover
Opaque cream for gentle removals on sensitive clients.
Lash adhesive or Glue
Cyanoacrylate-based glue used to bond extensions to natural lashes. Dry time, humidity tolerance and retention profile vary between brands. Shop our Lash Glue.
Superbonder or Sealant
Post-treatment sealant that cures the glue bond instantly. Locks the set in, reduces fumes, improves retention dramatically. Full Superbonder guide.
Nano mister
Small handheld device that sprays a fine water mist. Used after the set to cure the glue faster and reduce sting.
Glue ring
Small ring with a well for glue, worn on the non-dominant hand. Alternative to a glue stone.
Glue stone or Jade stone
Flat stone that slows glue drying so the bead stays workable longer. Placed on the workstation next to the tech.
Under-eye pad or Gel pad
Disposable pad applied to the lower lash line before the set. Protects the lower lashes and gives a clean mapping surface. Medical-grade hydrogel in premium brands.
Sensitive tape
Hypoallergenic tape for under-eye protection when gel pads irritate the client. Secures the lower lashes out of the way without pulling on the skin. Shop our Sensitive Tape.
Technique terms
Isolation
Using a second pair of tweezers to separate the one natural lash you want to attach an extension to. Bad isolation = multiple natural lashes glued together = damaged lashes.
1:1 ratio
One extension per natural lash. Classic set technical term.
Retention
How long the extensions stay on the natural lash. Measured in weeks and as a percentage at infill. 80% retention at 3 weeks is strong. 50% means something's gone wrong. Read the retention workflow guide.
Infill
A top-up appointment where you replace fallen extensions. Usually booked 2-3 weeks after the full set. Most studios charge 50-70% of the full set price for an infill.
Full set
The first appointment where you apply extensions to a clean lash line. Usually 90-150 minutes depending on the style.
Fill-in or Refill
Same as an infill.
Removal
Service where you take off all extensions using gel or cream remover. 20-40 minutes.
Fan placement
The angle and orientation of a fan on the natural lash. Proper placement (fan wrapped around the natural lash base) = strong retention. Sloppy placement = falls off in a week.
Heat-bonded fans
Fans with bases slightly melted together during manufacture. Strong base, less likely to unwrap mid-application.
Ventilation
Workspace air flow. Matters because cyanoacrylate gives off vapour. Good ventilation protects both tech and client.
Humidity
Amount of water vapour in the air, measured as a percentage. Affects how your glue cures. Most glues want 40-60% RH. Buy a hygrometer (£8 on Amazon).
Fibre types
Synthetic (PBT)
PBT (polybutylene terephthalate) is the standard fibre for professional lash extensions. Holds curl, doesn't react with skin, takes dye well. 95%+ of trays sold in the UK are PBT.
Silk
Marketing term for slightly softer PBT. Usually not actual silk fibre. Great for mid-weight classic sets.
Mink
Marketing term or, in rare cases, actual animal fibre. Most "mink" lashes are PBT. Genuine mink is rare and ethically contested, avoid.
Sable
Premium PBT with a softer, shinier finish. Used in higher-end trays.
Colours
Standard black
The default. Works on most clients.
Brown lashes
Brown-dyed PBT fibres. Important for blonde, honey, and light brunette clients who look washed out in black. Coffee Collection brown lashes here.
Latte (Pop Coffee Collection)
Light-medium brown. For blondes, honey-tones, light brunettes.
Mocha (Pop Coffee Collection)
Medium-dark brown. For medium-dark brunettes. Our bestselling Coffee shade.
Espresso (Pop Coffee Collection)
Deep brown, soft black replacement. For deep brunettes or clients who want the darkest option without the harsh black line.
Coloured lashes
Purple, blue, green, red, gold, silver. Mostly editorial or festival work. Not high volume but good for specialist studios.
Tools
Straight tweezers (I-shape)
General-purpose tweezer. Used for isolation and single-lash pick-up.
Curved tweezers (90 degree)
For picking pre-made fans or applying mega volume.
Boot tweezers (L-shape)
Angled for easier fan pick-up. Most volume techs carry a pair.
Dumpling tweezers
Wide, flat-tipped for fanning mega volume. Looks like a dumpling, hence the name.
Volume fan tweezers
Fine-tipped for hand-fanning. Specific to volume work.
Lash wands or Mascara spoolies
Disposable brushes for combing through the set during and after application. Also given to clients for at-home care.
Micro brush
Tiny bristled applicator for applying primer, remover or sealant precisely.
USB lash fan
Small handheld fan used at the end of the set to speed up glue curing.
Hygrometer
Device that measures temperature and humidity in the room. Every serious tech has one.
Business and client terms
Patch test
Applying a small amount of glue to the skin (usually behind the ear) 24-48 hours before the first set. Screens for allergic reactions. Industry-standard, insurance-mandated in the UK.
Client aftercare
Instructions given to the client for how to look after their set. Daily cleansing, no oil-based products, no sleeping face-down. Read the full aftercare guide.
Walk-in and Walk-out time
When the client enters and leaves. Used to check your appointment durations against industry benchmarks.
Chair time
Actual minutes of active lashing. A 2-hour appointment might be 90 minutes of chair time plus 30 minutes of consultation, mapping and aftercare.
Upcharge
Extra fee for a specific style or premium product. Coffee Collection adds £10-20. Brides add £20-30. Mega volume adds £15-25.
CPD
Continuing Professional Development. Your ongoing training hours. Insurance providers require a minimum annual CPD count.
NVQ, VTCT and ABT
UK qualifications recognised for lash technicians. NVQ Level 2/3 Beauty. VTCT-accredited courses. ABT (Associated Beauty Therapists) insurance-recognised training.
Glossary updates
We'll keep this page live and updated. If we've missed a term you use and want explaining, DM @popofbeauty_ and we'll add it on the next edit.
Shop the products mentioned above: Lash Glue, Pre-Treatment Primer, Superbonder Sealant, Lash Shampoo, Sensitive Tape, Coffee Collection.
It'll never be perfect. But it can be better.