To use hair fibers, start with clean, completely dry, styled hair. Part it where you normally wear it, shake a light layer of fibers onto the spots where scalp shows, then pat them in with your fingertips. Add more only where you still see scalp, and set everything with a light mist of hairspray.
Hair building fibers are tiny colored fibers that cling to the hair you already have, so a thin part, a wide part line or a see-through crown looks fuller right away. They are a cosmetic cover-up: they sit on your hair and wash out with shampoo. This guide covers the exact steps, how to keep a part or hairline looking real, how to choose a shade, and the mistakes that make fibers look obvious. If you are using our hair building fibers, read the directions on the pack too, and follow them where they differ from the general tips here.
What you need
- Hair fibers in a shade that matches your roots
- A spray applicator (optional, helpful for the hairline and a narrow part)
- A light-hold hairspray
- A mirror near a window, or a hand mirror for the crown
- A towel or an old T-shirt over your shoulders
How to use hair fibers, step by step
1. Start with clean, completely dry hair
Fibers hold on with static, and water or oil weakens that hold. Wash and dry your hair fully. Blow-drying makes sure the roots are dry too.
2. Style first, fibers second
Blow-dry, straighten or curl your hair before you add fibers. Put on any serum, cream or mousse first and let it dry. Products added on top of fibers can make them clump or slide off. Fibers should be the last step before hairspray.
3. Make your part
Part your hair exactly where you wear it, so you are covering the area people actually see. For a wide part line, this is the main area to fill. For the crown, use a second mirror to see the back of your head.
4. Shake on a light layer
Open the bottle and hold it a few inches above the area, tilted at about a 45-degree angle. Shake or tap gently so a thin layer falls onto the scalp and the hair around it. Start with less than you think you need. You can always add more, but too much is hard to remove without washing it out.
5. Pat it in with your fingertips
Press the fibers gently into the hair on both sides of the part with your fingertips. Patting helps them cling to the strands instead of sitting loose on top. Avoid combing or brushing through after you apply them, because that can knock fibers out.
6. Check in daylight and touch up
Check in a mirror near a window; indoor bulbs hide patchy spots. Add a little more only where scalp still shows, then pat again.
7. Set it with hairspray
Mist a light hold hairspray over the area from arm's length and let it dry before touching your hair. This helps the fibers stay in place through the day.
How to use hair fibers on a part, hairline or crown
A wide part line: this is the most common place women use fibers. Work along the part in short sections. A slightly zig-zag part, or one moved a little to the side, also hides a wide part better than a sharp center line.
The hairline: go lightest here, because a heavy line at the front looks drawn on. A spray applicator, or a piece of card held along your forehead as a guard, keeps fibers off your skin. Wipe any fibers off your forehead with a dry tissue.
The crown: use two mirrors, shake from above, then pat with your fingertips. If you wear a ponytail or a bun, fill the part and any spots where the hair pulls tight before you tie it up.
How to choose your hair fiber shade
Match your root color, not your ends, because fibers sit right at the scalp. If you are between two shades, the darker one usually blends better. With highlights, balayage or gray blending, layering a base shade with a lighter one often blends better than a single flat color.
Our hair building fibers come in 25 g bottles in black, dark brown, medium brown, light brown, auburn, light blonde, golden blonde, golden medium blonde, grey and white for $28.20 each, plus a 12 g white bottle for $23.50. The spray applicator is sold separately for $18.80, and multi-shade sets are also listed on the product page.
Common mistakes that make fibers look fake
- Using too much at once. A heavy layer makes the part look flat or painted on. Build up thin layers.
- Applying to damp or oily hair. Fibers clump and will not spread evenly. Dry hair fully first.
- Adding oil or serum on top. Put all products on first and let them dry before you add fibers.
- Brushing afterwards. Pat with your fingertips instead, and do any combing before the fibers go on.
- Choosing a shade by your ends. Match the roots, and check in daylight.
Hair fibers vs. hair dye: which do you need?
They do different jobs. Fibers add the look of density where scalp shows through, for one day at a time, and wash out with your next shampoo. Hair dye changes the color of the hair you have, for example to cover gray roots, and lasts for weeks. Some women use both: color to blend gray, and fibers on the days the part looks thin. If color is what you need, our guide on how to use hair dye shampoo walks through it, including the 48-hour patch test to do before any hair dye.
Washing fibers out and day-to-day tips
Regular shampoo washes fibers out, and you do not need a special remover. With long or thick hair, shampoo in sections and rinse well. Many people wash fibers out before bed, or use a dark pillowcase if they leave them in overnight. Fibers can rub onto pale collars, hats and pillowcases, so a light mist of hairspray and darker fabrics help on the first few days while you find the right amount. Heavy rain, swimming or a hard workout can make fibers shift, so plan your touch-ups around those.
Read the ingredient list on the packaging before use, especially if you have a sensitive scalp or known allergies, and stop using fibers if your scalp becomes irritated. Fibers cover thinning; they do not treat it, so if you notice new or sudden thinning, talk to a doctor or dermatologist about the cause.
Where to buy hair building fibers online
You can order our hair building fibers in ten 25 g shades, with the applicator as an add-on. Every US order ships free, and you can use code WELCOME15 for 15% off (one use per customer). Browse more styling and color products in our hair care collection.
FAQ
How do you use hair fibers?
Start with clean, completely dry, styled hair. Part it, then shake a light layer of fibers onto the area where scalp shows, holding the bottle a few inches away. Pat them in with your fingertips, add more only where needed, and finish with a light mist of hairspray.
Do you put hair fibers on wet or dry hair?
Dry hair. Fibers cling to your strands with static, and moisture stops them from spreading evenly, so blow-dry and style first, let any cream or serum dry fully, and apply fibers as the last step before hairspray.
How long do hair fibers last?
Usually until your next shampoo, since regular shampoo washes them out. A light hairspray helps them stay put during the day, but heavy rain, swimming or a hard workout can make them shift or run.
Can you apply hair fibers without an applicator?
Yes. Shaking the bottle gently over the area works well for a part or the crown. A spray applicator gives more control on a narrow part or along the hairline, and ours is sold separately.
What color hair fibers should I get?
Match the color of your roots, not your ends or highlights, because fibers sit at the scalp. If you are between two shades, the darker one usually blends better. With highlights or gray blending, layering two shades can blend better.