There are several printable polyhedral dice on Thingiverse, but the only full set:
Has very rounded corners that I'm not fond of, since they take too long to stop rolling and don't have the nostalgia value of sharp edged dice for me.
Most of the sharp edged dice on Thingiverse don't have the numbers engraved and are really just platonic solids or use non-standard designs.
There already is a sharp D12: http://www.thingiverse.com/thing:550
And a really nice sharp-edged D20: http://www.thingiverse.com/thing:551
As well as an almost sharp D10: http://www.thingiverse.com/thing:3018
You can find my second die, the D6, here: http://www.thingiverse.com/thing:33307
I want to fill in the missing dice so that there's a full set of sharp-edged, old-school polyhedral dice on Thingiverse. This is my first contribution, the D4. It does not have rounded edges, but to protect bare feet and in keeping with the tradition of the old school dice, I've flattened off each of the four corners.
I place no restrictions on the use of this file or the original Blender file (attached, use 2.64+).
No assembly required, should just be able to print and go.