Do any of the these from their website fit that profile?

> Various types of liquid polymers such as natural Latex, silicon, polyurethane and Teflon, as well as variety of textile fibres such as cotton, viscose and polyamide enable tailor-made fabrics for any need.

http://www.tamicare.com/#!technology/c1xu8

Yes, latex and cotton are biodegradable.

3D printed teflon and polyamide would be great, those are excellent materials with plenty of applications beyond clothing.

Cotton is most definitely biodegradable (but of course, not a plastic).

I imagine the slogan is something like, "Reduce > reuse > recycle > compost."

Just because PLA biodegrades doesn't make it more environmentally friendly than other sources of reusable underwear that also biodegrades....

Printing durable textiles at home sure would be cool, though.

The theoretical advantage of biopolymers isn't just that they biodegrade, it's that they biodegrade into materials (like methane) which can form the feedstock for bacteria which in turn produce the biopolymers. This is better than paper underwear because the paper->CO2->tree->paper cycle is much slower.

Ain't nothing wrong with being a hippie when you're right.

Not necessarily, if the materials are chosen well you could recycle them. Not necessarily an improvement in terms of total energy use but worth evaluating.

More importantly is to build recycling tech so that such disposable items can be broken down into raw material for 3D printing more ... whatever.