CDC’s Guide to Masks

The CDC’s latest e-newsletter from February 16, 2021 highlights different types of masks, the best ways to use them and how to improve their fit to get the best protection.

Masks help prevent people from getting and spreading COVID-19. They provide a barrier that keeps respiratory droplets from spreading. Correct and consistent mask use is a critical step everyone can take to prevent getting and spreading COVID-19.

Masks work best when everyone wears them, but not all masks provide the same protection. When choosing a mask, look at how well it fits, how well it filters the air, and how many layers it has.

Improve How Your Mask Protects You

Ways to make sure your mask works the best it can:

  • Make sure your mask fits snugly against your face. Gaps can let air with respiratory droplets leak in and out around the edges of the mask.
  • Pick a mask with layers to keep your respiratory droplets in and others’ out. A mask with layers will stop more respiratory droplets getting inside your mask or escaping from your mask if you are sick.

Choose a mask with a Nose Wire

  • A nose wire is a metal strip along the top of the mask
  • Nose wires prevent air from leaking out of the top of the mask.
  • Bend the nose wire over your nose to fit close to your face.

Use a Mask Fitter or Brace

  • Use a mask fitter or brace over a disposable mask or a cloth mask to prevent air from leaking around the edges of the mask.
Illustration of a woman wearing a mask with an adjustable wire nose piece and a green checkmark in the corner
Illustration of a man wearing a mask with a mask brace or mask fitter on top of his mask with a gren check in the right top corner

Check that it Fits Snugly over your nose, mouth, and chin

  • Check for gaps by cupping your hands around the outside edges of the mask.
  • Make sure no air is flowing from the area near your eyes or from the sides of the mask.
  • If the mask has a good fit, you will feel warm air come through the front of the mask and may be able to see the mask material move in and out with each breath.

Knot and Tuck ear loops of a 3-ply mask

  • Knot the ear loops of a 3-ply face mask where they join the edge of the mask
  • Fold and tuck the unneeded material under the edges
  • For video instructions, see:
Illustration of a person cupping their hands by the sides of their mask to check for air gaps with a check in the upper right corner
Illustration of a woman wearing a face mask with knotted loops and illustration of how to knot mask loops.


Adding more layers of material to a mask (layering) is a good way to reduce the number of respiratory droplets containing the virus that come through the mask. One layering strategy is to use a cloth mask that has multiple layers of fabric. Another strategy is to wear two masks or a “double mask.”

Improve Mask Fit and Filtration by Wearing Two Masks (Wearing a “Double Mask”)

Wearing a second mask on top of a first mask (to create a “double mask”) can:

  • Improve fit by pressing the inner mask closer to the face, thereby reducing the amount of air that leaks around the edges of the masks.
  • Improve filtration by adding more layers of material to reduce the number of respiratory droplets containing the virus that come through the masks.

One way to do this is to wear a medical procedure mask underneath a cloth mask. A recent study conducted in a laboratory found that this “double mask” combination provided much better protection to the wearer and to others as compared with a cloth mask by itself or a medical procedure mask by itself.

Always make sure you can see and breathe easily!

Illustration of adding a disposable mask with a cloth mask with a wire nosepiece to make a double mask with a green checkmark in the corner
Illustration of a woman wearing a disposable mask with a cloth mask over for a layered mask

There are some mask combinations that should not be used to “double mask.”

  • Do not combine two medical procedure masks or two disposable masks to create a “double mask.” Medical procedure and disposable masks are not designed to fit tightly and wearing a second medical procedure / disposable mask on top of the first medical procedure / disposable mask does not help to improve the fit.
  • Do not combine a KN95 mask with any other masks. You should only use one KN95 mask at a time, and you should not use any type of second mask on top of or underneath a KN95 mask.
Illustration of a woman wearing two disposable masks and a red x in the upper right corner
Illustration of a man wearing a KN95 mask with another mask over it and a red x in the upper right corner

For more information on science behind improving how your mask protects you, see Improve the Fit and Filtration of Your Mask to Reduce the Spread of COVID-19.

Remember! Masks should not be worn:

Types of Masks

There are many types of masks you can use to protect yourself and others from getting and spreading COVID-19. Cloth masks can be made from a variety of fabrics, and many types of cloth masks are available.

  • DO: Look for a cloth mask that is made of multiple layers of tightly woven, breathable fabric.
  • DO: Make sure your cloth mask blocks light from coming through the fabric if held up to a bright light source.
  • DO NOT: Wear cloth masks with exhalation valves or vents, single layer or masks made of thin fabric that don’t block light. Disposable face masks are widely available.
  • DO NOT: Wear disposable masks with gaps around the sides of the face or nose, or if wet or dirty.

CDC’s Guide to Masks

Wear a mask correctly and consistently for the best protection. Be sure to wash your hands or use hand sanitizer before putting on a mask and do not touch the mask when wearing it. If you have to often touch/adjust your mask, it doesn’t fit you properly, and you may need to find a different mask or make adjustments. 

Check out the CDC’s complete updated Guide to Masks.

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