BolivAIR – 3D Printable, Breathable Handkerchief Alternatives using HEPA filters

These are not intended to replace N95 respirators. They are only intended to be a hopefully better “plan B” if, God forbid, medical workers are left with only a handkerchief to protect themselves from COVID-19. This is a 3D-printable respirator backup plan. If you have access to N95 respirators, wear those instead.

This is *not* a Keith’s Test Garage project. I’m just the only volunteer who had a website. We are currently producing these for a specific hospital, but we are making the in-progress STL files available below in case anyone wants to test them, improve them, etc.

Over the past few days, we’ve been collaborating directly with a hospital to build a 3D-printable handkerchief alternative with the following considerations: 

  • Reliable seal around the face, even when moving around
  • Uses HEPA filter media, yet easy to breathe through & communicate
  • Easy to print
  • Reasonably comfortable for long periods of time
  • Feasible to deploy from the community to the hospital in large numbers

This is a work-in-progress. We will update the design based on continued feedback from the hospital.

The BolivAIR


This model has not been approved by any regulatory agency. Use it at your own risk, and only as a last resort, if you do not have any other homologated protection. The recommended measures to protect yourself from infection with the coronavirus COVID-19 are the following:

• Stay home and avoid contact with other people
• Avoid touching your face with your hands
• Wash your hands very often

See for more information about protecting yourself from COV-19.

Changes We Made

  • Enlarged filter area to allow usage of HEPA filter media & improve breathability
  • Increased strap hole size to allow 1/2″ and 3/4″ elastic for a comfortable, secure fit.
  • Mounted filter outside to reduce risk of inhaling fibers from the cut filter

Origins / Credits

The face profile came from this Thingiverse model, which was a remix of this 3D printable respirator mask.
The face-seal implementation came from Lowell Makes.  Go there for details about that. 

Some volunteers are printing the plastic, some are installing the straps, some are installing the foam rubber, but the hospital clinics & physicians will be installing the filters and conducting Qualitative Fit Testing.

Various Prototypes & Iterations

Here are a few 3D printable respirator masks we tried/modified/tested/hacked over the past few days.

Explain “we” and “our.”

Since I typically fly solo on this channel, the “we” requires an explanation.

I’m primarily referring to Matt Winder, Matt Havens, and I, as we did the up-front prototyping and coordination with the hospital. During that time, several others have been giving input, challenging ideas, testing prototypes, and preparing their printers to start cranking out 3D-printed respirator masks. Now that we have approval, the larger team is ready to go.

A dead thing can go with the stream, but only a living thing can go against it.

G. K. Chesterton

While you’re here…