Making your own face mask? Some fabrics work better than others, study finds
Other hospitals, such as Vanderbilt University Medical Center in Nashville, have also suggested using tightly woven fabrics for do-it-yourself facial coverings. Kaiser Permanente has also published instructions on DIY masks, also calling for two layers of cotton fabrics.
Cotton T-shirts, however, may not be as useful. A 2013 study published in the journal Disaster Medicine and Public Health Preparedness compared medical grade surgical masks with homemade facial coverings using plain cotton T-shirts. The surgical masks were found to be three times more effective in blocking small particles than the T-shirts.