Eyebrow thickness might come in and out of style (think Brooke Shields’ desirable eighties brows versus pencil-thin nineties supermodels), but no matter what the brow trend of the moment may be, fuller eyebrows signal youth. Period. Because brows often thin with age, extremely thin brows may make us look older than we really are.Young women who are still enjoying their lush, youthful brows often make the mistake of over-tweezing—and often live to regret it.Nurse Jean Melby, 55, is like many others. “As a teen, thick brows were definitely uncool and I got busy with my tweezers. In my 30s, I realized they were over-plucked and asymmetrical and my despair began anew,” she says.MORE: Your Best Brows Products have flooded the market to fill in the need for full brows: Brow pencils, powders, tints, gels with fibers, and more. New treatments color far outside the lines of brow pencils, getting creative with conditioners, Latisse (intended for eyelashes and used “off label” for brows) and even eyebrow transplants (yikes!).Over-plucking aside, there are more serious reasons why people want fuller brows. Some lose brow hairs from thyroid disorders, alopecia (hair loss) or chemotherapy.Which brings us to permanent brow tattoos, and the less intimidating semi-permanent makeup services, which have popped up in select salons worldwide.(Permanent brow tattoos have a bad reputation for a reason. As your skin ages and sags, so do the tattoos, which can result in bizarre, blue-ish faded ink.)New York City’s Browhaus takes a gentle approach to tattooing with all-natural vegetable dye applied with a carving tool during their “Brow Resurrection” service. It takes two hours and fades after about two years.After Jean hesitated because of the cost (nearly a grand), she went for it. Twenty-nine year-old accountant Esther also decided to get semi-permanent brows, because she has naturally sparse brows. “I knew the importance of having the right brows for your face because it could completely enhance your look,” says Esther. “But I also was tired of always filling in and touching up my brows every day.”Other women have gotten this treatment after losing their brows from alopecia (hair loss) or chemotherapy.Here’s what to know if you opt for a semi-permanent brow treatment:1. You customize your brows.Aestheticians ask for your desired thickness, color and arch. They’ll pencil-draw your brows first to make sure the shape and shade is spot-on. You can figure out the best brows for your face shape ahead of time, or have the aesthetician help you. Note: It’s important to have a neutral face when it’s drawn on, instead of making a facial expression!QUIZ: Find Your Face Shape2. It shouldn’t hurt.Browhaus describes the Brow Resurrection as “near painless,” and those who’ve had a semi-permanent brow service elsewhere agree. You’ll feel some pressure, “scratching,” or plucking (paradoxically, no tweezing occurs!) from the tiny pins. That’s thanks to the numbing cream you can have applied prior.3. It will fade. This is a good and bad thing, depending on how you see it. “There was some fading which I am glad of,” Jean says. “After the first few weeks it looked a more normal shade of black and not such a stark difference on my pale skin.”Esther had a similar experience. “After the initial first service, I was very shocked by how harsh my brows looked. It literally looked like someone drew on me with a marker. It is true that the lines do indeed soften.”If it fades too quickly, you can go back. Jean and Esther both took advantage of touchups, which are recommended after about two months.4. You have to care for your “brows”You cannot get your brows wet for a week, and need to hold off on swimming and facials for two weeks. Avoid heavy workouts, excessive sun and makeup until it’s healed.Browhaus recommends you let the scabbing come and go. Other places advise you apply Vaseline every hour for the first week, to avoid scabbing.5. It’s an investmentThe Brow Resurrection costs nearly $1,000. Esther had a similar service done for $350 in Canada. You may think you can’t buy enough brow pencils in two years to make up for that cost, but you’re saving time, too. “I can get away with wearing less eye makeup because my eyes are more defined and prominent,” Esther says.MORE: The Best Brows for Your Face Shape6. It’s a safer bet than permanent.If the tattoo’s so great, why not get it done permanently? Well, tattoos may become discolored with time, say, from black to blue to green.Also, with semi-permanent, you’re not out of luck if your brow shape is totally “out.” “I have stylish brows that are in vogue at the moment,” Jean says.Aside from looking better according to the trends of the time, you can gain a sense of confidence from doing any beauty treatment you ordinarily wouldn’t spring for.“I do like the feeling of having done something kind for myself that made me feel better. While I do think I look better, that is truly secondary,” Jean says.QUIZ: Are You Happy With Your Face?