Natural Nails

What’s in a File?

From filing to shaping, a nail file is one of the most important tools in any nail service. Use this guide to prep you on files — from grit types and what files are made of to what to look for in a quality abrasive.

Wood was the first substrate used in making files and it's still popular. It's inexpensive and rigid. 
<p>Wood was the first substrate used in making files and it's still popular. It's inexpensive and rigid.&nbsp;</p>

We can bet that Flowery Beauty Products never imagined nail files would evolve the way they have. In 1910, the company invented the disposable emery board as an alternative to metal cross-cut nail files that were all the rage at the time. Today, there is a wide range of styles and materials to suit even the most discerning nail tech and client.

Where would a nail tech be without her trusty file? From filing to shaping, a nail file is one of the most important tools in any nail service. While the basic construction of an abrasive adhered to a backing and attached to a core has changed little since that fateful day more than 90 years ago, changes have come in materials and styles.

We’ve put together this nail file primer to give you inside information on the trusty tool you use to beautify your clients’ nails.


You could use the same file for all services, but luckily, there are specific files for just about any type of service. We asked nail technicians to fill us in on what types of files they like to use for different services.

NATURAL NAILS: Natural nails are thinner, softer, and more vulnerable to damage than artificial nails, so use special handling when filing. Improper filing can separate and damage layers of the natural nail, leading to peeling, splitting, and cracking.

“I shape the nail with a 180-grit file. To remove the white frayed edges from the nail I use a 240-grit file. I never use a 100-grit file on natural nails.” — Salina Rush, Studio 10 Hair & Nail Design, Wooster, Ohio.

For natural nails I only use a glass file. The glass file feels better to the client and seals the free edge to pre­vent layering or peeling — you can even use it in a seesaw motion without fear of damage to the nail, such as fraying.” — Tanis Darling, Burlington, Ontario

ACRYLICS: Acrylic nail services are one of the most popular nail services around, so it’s no wonder there are plenty of filing choices.

“For fills, I buff the nail with a 100-grit file, fill it with acrylic, then go over it again with the same file Then I’ll use my 180-grit file and finish with a 240 grit.” — Rush

“In a competition, after I’ve laid the acrylic, I lightly shape with a 220- to a 310-grit file and then use a buffing block to buff the nails. I usually start with a 220-grit file. Anything less than that can leave deep, heavy grit marks.” John Hauk, Belle A’Rever, Centerville, Ohio

WRAPS: Although wraps — fiberglass, silk, paper, or linen are harder than natural nails, they are softer than acrylic. Use a light filing touch so you don’t break through the fabric mesh.

“For fiberglass nails, I normally use a 180-grit file. I don’t need to use a 100-grit file.” — Rush

“I use a 180-grit file to take down length and a 240- grit file to smooth the nail.” — Patricia Yankee-Williams, Pattie’s Place, Baldwin, N Y.

GELS: You can do finishing work on gels, but be gentle since gels are softer and easier to file than acrylics.

“I’ll either use a 100- or 180-grit file to buff down the natural nail surface.” —Rush

“I usually start with 180-grit file. It doesn’t matter if I’m working with gels, wraps, or acrylics.” — Hauk


Nail files contain three main components: the abrasive, the material the abrasive attaches to, and the core to which the material is attached.

Most colored and cushioned boards have thin pieces of plastic in the middle. The abrasive-coated surface is then attached to the plastic core, which makes it strong and rigid.

Cushioned files have two layers of foam or cushion attached to both sides of the plastic core. A layer of foam is adhered to each side of the plastic. The abrasive is then placed on each side of the foam.

Adhesives are used to adhere the abrasive to a surface and to adhere each file layer together.

After all of these materials are combined in a large sheet, the files are cut out with a die cutter. Common ways to cut out files include the straight method or the Z-cut method. The straight method is a simple downward cut that produces a clean edge, while the Z-cut looks as though the edge is serrated or has Z- shaped marks on it. However, both methods have the same intention in mind: to reduce the razor-sharp edges that could potentially cut a client during filing.

Some files such as cushioned boards are cut out one by one to ensure a clean adge on each file Thinner boards can be cut out several at a time.


Ever wondered what materials are used in a file? Here’s a guide to some common materials used.


ALUMINUM OXIDE: A chemical compound widely found in nature; only abrasive that can be dyed; individual crystals have less dramatic peaks and valleys than silicon carbide; grit will fall off easier when filing; tends to rough up the nail because of the grit shape.

COMPRESSED ALUMINUM OXIDE: Compressed and bonded with porcelain, it results in a filing stone- It’s best for shaping and smoothing natural nails and doesn’t absorb water or chemicals. It can be used like a pumice stone to remove excess cuticle and hangnails.

GARNET: Most commonly used on wood files. Garnet is a mined mineral that is hard and durable.

SILICON CARBIDE: A bluish-black or green synthetic crystalline compound. Individual crystals have jagged edges with high peaks and valleys; cuts deeper, faster; tends to shed black dust on the nails during use.

SILICON CARBIDE WITH ZINC STERATE COATING (ZEBRA): The zinc sterate coating is a lubricant that prevents the grit from loading up with filing dust; grit feels smoother than the same grit of other abrasives.


CLOTH: Cotton is most commonly used; the most flexible of all abrasive backings; higher-cost backing; long-lasting; won’t crease, abrasives tend to imbed in the cloth, resulting in less aggressive cutting action; commonly found on buffers.

MYLAR: Trade name for polyester film; washable; durable and long-lasting; more expensive than files with paper backings.

PAPER: The first abrasive backing used on the original wood garnet files; inexpensive, durable; not water-resistant

WATERPROOF PAPER: Paper impregnated with an oil resin; dark gray or black in color; can be immersed in water.


FOAM: Polyethylene is the most commonly used foam; dense, closed-cell foam is waterproof and firm (open-cell foam absorbs water and is more spongy), allows file to contour to nail, allowing file action on more than one contact point; requires more pressure for filing, on some files the abrasive is embedded in foam without a backing.

PLASTIC: High-impact polystyrene is most commonly used; more flexible than wood; commonly overlaid with polyethylene foam in cushioned files; without a polyethylene foam overlay the plastic tends to transmit more vibration to a nail tech’s hand than a wood substrate; look for a plastic core that is neither so rigid it won’t give or so flexible it bends easily when pressed on the nail surface.

WOOD: First substrate used to make files; still popular; inexpensive; rigid.


Never let a nail file’s appearance deceive you; get up close and take a good look before you buy. ‘“Good files are made out of good materials that hold together and wear well,” says Michael Falley, CEO of Realys Inc./Tropical Shine.

Less expensive files can be more costly in the long run. They can shed grit and wear out quickly, buckle and crease, become too flexible, and cut cuticles if they’re not evenly cut.

“The most important aspect of a file is quality in manufacturing,” says Zailyn Prada-Blackburn, sales and marketing manager for Rudolph International.

“There should be a total lamination of the abrasives to the foam and to the plastic nail file core and an even cut on the sides of the file.

“Also, the foam materials that sandwich the abrasive to the plastic should be closed cell foam to prevent absorption of liquids. Open cell foam can allow mold and mildew to build up.”

You can do several things to gauge the quality of a nail file. “Generally, better files have a degree of rigidity,” says Geoff Geils, president of Flowery Beauty Products. “This requires less pressure and wrist movement because the file won’t bend as much. This also means there is better control and contact with the exact spot you want to file.”

A wood file should never be flimsy because it will require you to apply more pressure when you’re filing. Look at the lamination of the paper, which should contain no splits or frayed edges. Also look at the paper for a richer-looking abrasive and a uniformity of grit.

If you’re looking at a silicon carbide file, check the rigidity and the die cut. The side of the file should be black or dark gray, which is the oil resin coating on the inside.

Cushioned files should be rigid. If they flex too much the paper can crack and break. When you push on the surface of the file it should pop right back out. With cheaper cushioned files it’s much easier to feel the core.

Of course, it’s important to consider your clients as well. If you have a younger clientele, think about purchasing fun, colorful files that you can also retail.

With so many files, how’s a nail tech to choose? Houshang Rastegar, president of H&H Nail Products, says every nail tech should have at least three types of files — and a buffer. He recommends investing in a coarse, medium, and fine nail file.

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