First things first. To print this, you'll need three different kinds of filament: (1) Something rigid like PLA or PETG; (2) Something extremely flexible like TPU or FlexPLA; and (3) Nylon.

There is a design of styling hairbrush that was popular in the 80's through the early 2000's, but which is becoming increasingly difficult to find. The brush component of these brushes consisted of nylon bristles held in place by a typically latex holder that was folded in such a way as to give the bristles good spacing and a reasonable amount of "give" when in use.

For some reason, this style of hairbrush has become increasingly difficult to locate, so I decided to design my own for 3D printing.

In order to have the right amount of "give" while still remaining sufficiently stiff and slick, the bristles are printed in nylon. I don't think there's any reasonable substitute for this, but if you have good luck with some other material, please leave a comment.

In addition to needing a certain amount of flexibility for comfort purposes, the bristle holder needs to be folded under itself after printing for insertion into the handle. I have used TPU for this purpose, although I imagine that any highly-flexible material should work.

The handle can be anything you want, as long as it's stiff enough to hold the bristle holder in place after it has been folded. I used PLA during development, and made my final print with PETG. Both work fine. It is even possible that you could print the handle in nylon if you want something with a little more flexibility.

Finally, this is a compact version of a hairbrush. This is due to the limitations of the printer I'm using, which has a 120x120mm print bed. The design itself is parametric, and although I haven't tested changing dimensions around to create a full-sized hairbrush, the length and number of bristle rows does change appropriately as the parameters in brush-common.scad are tweaked.

Since these brushes are no longer readily commercially available (at least in the US), I'm considering this a "Life Hack."