Once reserved for proms and weddings and then peeled off at the end of the night, eyelash extensions now add a dose of glamour to everyday life. If you’re considering them, you may have some questions. Don't worry, we're here to provide some answers and to help you feel prepared to get the type of lashes an old porcelain doll stashed in the attic would kill for.

What are eyelash extensions?

Lash extensions are tiny black fibers that resemble eyelashes and that are attached to natural eyelashes using glue. The fibers either come as individual pieces or attached to a strip. Strip lashes can be applied by anyone. Professionals typically apply individual lashes. Our guide focuses on the latter because they're more complicated, not to mention expensive.

How do eyelash extensions work?

Licensed technicians carefully apply fake lashes by attaching the tiny extensions one-by-one to create a look that's both dramatic yet natural. After the service, lash extensions will last through a full growth cycle of your natural eyelashes. Though each person’s lash growth may vary, this process is generally between six to eight weeks. However, most technicians recommend touch-ups every three to four weeks.

What are they made out of?

The most common extension materials are mink, synthetic hair, and synthetic silk. Mink extensions tend to be the lightest and softest, which is why some people believe they're the best fake eyelashes. It's also why they're the most expensive. Synthetic lashes are typically the thickest and heaviest of the bunch, resulting in a highly dramatic look. Synthetic silk extensions are the most common type of extensions used nowadays because they tend to be fairly light, very dark, and able to hold a curl.

How much do eyelash extensions cost?

Lash extensions range in cost, depending on the type of material used. But generally, an initial full-set lash application will cost somewhere between £80 and £130. Luckily, you can snag a full set on Groupon for as little as £40-60.

How many extensions do I need?

You have to decide if you want a full set or partial set. If you want a full set, you'll need as many extensions as you have eyelashes—about 80–120 per eye. A full set gives you a highly glamorous, dramatic look. If you want a partial set, a good option for newbies and those who want just a little enhancement, you'll need about 35–40 per eye.

How are they applied?

A technician applies patches to the undereye area to help hold down your bottom lashes. She then applies a primer to your upper lashes before using tweezers to fan out your lashes and isolate one of them. With her other hand, the tech picks up a tiny extension using another pair of tweezers, dips the extension in glue, and carefully attaches it on top of the isolated natural eyelash. Your eyes stay closed throughout the whole process.

How long does the application process take?

Because the application process is so meticulous, getting a full set can take 2.5–3 hours. Most clients use the time to nap. Half sets and touch-ups take considerably less time.

How long do extensions last?

The lifespan of the extensions hinges on the growth cycle of your natural lashes. Natural lashes fall out every 6–8 weeks before regrowing, which means that extensions fall out when the natural lashes they're attached to fall out. Most reputable salons suggest that extensions can last up to six weeks with proper care, but touch-ups are recommended every three weeks to keep the extensions looking their best.

How can I make them last longer?

• Avoid getting new lashes wet for 24–48 hours (also avoid getting very sweaty during this
  time).
• Avoid using oil-based products, any products that include glycol, and waterproof
  mascara.
• Avoid using anything that's moisture-rich, such as lotion, shampoo, conditioner,
  and face wash, near your eyes. A pair of goggles in the shower might help.

Can I still wear eye makeup with extensions?

To some extent, yes. You can't use oil-based or waterproof mascara, which can dissolve the glue. In fact, applying mascara can also tug at the extensions, causing them to fall out sooner. Luckily, most people find they don't need to wear it when they have extensions. If you can't face three weeks without mascara, though, go ahead and gently apply it to the very ends of the lashes, avoiding the roots. Using any other eye makeup should be fine as long as you take it off carefully using an oil-free eye-makeup remover.