This is a basic design for a clip meant to be sewn on diy facemasks. Using this and a standard 1/4"(6mm) braided elastic strap you can have a fasm that can be shared(if thoroughly washes/sanitized between users) or produced in bulk without having to fit the ear loop yourself!

[If you have a bias tape/rear tie based mask, maybe check out this model instead]

Also, reminder that 3D printed facemasks DO NOT WORK. This is for use in a sewn mask.

This clip should be printed with the details provided and used on a sewn DIY mask(or anything else that requires an elastic strap under mild tension).

There are four holes at the base of the clip. Three are for sewing, the fourth is a rectangular slot for use with strapping. 

This was tested with PLA. Which means I can't guarantee it will work with other more rigid plastics. However, that does mean that it has a low warping temperature (as low or lower than 100C) so if you need to wash your mask or expose it to temperatures higher than that, instead of sewing to the mask directly, consider a strap that can be clipped on and off and slotted through the slot at the base. You can probably wash or soak the clip in alcohol or some other PLA safe disinfectant.

Instructions on how to use this clip and an example can be found here: https://youtu.be/8EBdFEUTopM

The idea of this clip is to provide a tension based mechanism for allowing you to easily tighten an elastic that wraps around your head, pulling in your mask tighter, and being somewhat more 'one size fits all'.

I suggest the use of four clips per mask, two per side, for two straps on both the tops and bottoms of the ears (see pictures). Carefully (but forcefully) "snap" the middle grabber bit until it rests above the claws on the frame. Thread in the elastic band and leave enough slack for it to slip over your head. Once where you need it to be, pull on the threaded ends of the elastic to tighten to the appropriate tightness.

The clip will not be tough enough to bear any load but it ought to be enough to keep the mask snug.

As the pushing through of the grabber can be finicky and sometimes even break, I suggest printing a few spares until you know you have enough for your mask(s).

Please share or even remix! If you do remix this, please leave a link in the comments, I'd love to see it!

I only put enough conditions on the license to make sure it stays freely accessible to all.

If making masks for a hospital/health clinic, please check with them first. As many will prefer to attach their own straps/elastics and filters.