This is an extension to the model I uploaded here. Basically, this is another way to have an adjustable mechanism for facemasks (or costumes!) but this time for facemasks that employ rear tie bias tape or straps, given elastic can be uncomfortable for some or difficult to get a hold of lately.
I have long hair, and when tying those masks around the back of my head, even if I gather my hair into a ponytail, I'll invariably get some caught in the knot and it hurts.
This is clasp system that can be 3D printed without support material and very easily/cheaply. It employs a friction based adjustable 'grabber' to tighten it to your head's size (don't tighten it too tightly though!). And a slide-lock clasp so easily attach it to the back of your head without getting much hair caught in it(and even if it does, it won't pull your hair).
See the pictures on this upload for instructions.
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.