The filter that we sent with your mask is made from two layers of shop towels. Shop towels have been shown to an effective material use for a filter. Click here to read more about it. You can wash your filter 2-3 times in hot water, dry and reuse.
To make your own filter, cut a 7 1/2″ square of shop towel and fold in half. Insert into your mask.
“But what if I don’t have shop towels?”
You can use a coffee filter, though this has been shown to be a little more difficult to breath through. In a pinch, you could also use regular paper towel. Our fitted masks are made from 3 layers of cotton (a plain weave cotton for both front and back and a layer of cotton flannel on the inside), and our pleated masks are made from 2 layers of cotton. Even if you use it without a filter, your mask can still help to keep most of your germs inside.
If you would like to purchase additional filters, you can do so here.
There is lots of information available about different types of filters and their effectiveness. Although we cannot speak to it’s accuracy, click here for a source we thought to be informative.