Truncated Sphere D15.

This die is inspired by the repulsive force polyhedra although in this case, the underlying polyhedron (not rounded) is very different from the shape that can be obtained through this technique with 15 points repulsing each others.
Actually, I calculated the positions of points (5 at each tropic, 5 at equator, none at the pole) to have a maximal radius for the circles resulting from the intersection of this underlying polyhedron with a sphere. The result is a truncated sphere with 15 circular faces of same radius.

It is numbered from 1 to 15: all numbers are on edges.
The sum of the numbers on each tropic is 40 and the same applies to the equator.
Except for 8, all the numbers go by pair summing to 16: on the tropic two numbers symmetric relatively to the plane of the equator sum to16 and on the equator circle itself two numbers symmetric relatively to number 8 sum to 16. 

This die is made of a shell of 1.5 mm that contains support material to make it heavier. The engraved numbers have a 0.75 mm depth.

More informations in this post.

Available Truncated Sphere Dice: D4, D6, D8, D9, D10, D%, D11, D12, D14, D15, D16, D17, D18, D20, D24, D32, D33
Alternative shapes: alt D8, 3-fold D10 (rounded), 3-fold D10 (pointed), 4-fold D10, 5-folded D10 (pointed)
Coming soon: D22, D50
Related dice: Concave D4, Concave D6, D4 Shell, D8 Shell.

Breaking news!
The KickStarter project has been sucessful!
Thank you all!
This die will be mass produced in March 2013!

D18 Sphere

This is a Truncated Sphere D18.

The numbering has been done very carefully. Of course, numbers on opposite faces sum to 19. This leads to the fact that the 8 numbers around any of the 3 diameters sum to 76. But the dificulty has been the have the 6 numbers surrounding a spherical zone to sum to 57. It works for all the 8 zones (for instance, in the rendering - the brown one - you can see: 18 + 3 + 13 +11 + 7 + 5 = 57).

See this thread for more informations.

Available Truncated Sphere Dice: D1, D3, D4, D5, D6, D7, D8, D9, D10, D%, D11, D12, D13, D14, D15, D16, D17, D18, D19, D20, D24, D32, D33
Alternative shapes: alt D6 (3-fold), alt D7 (2-fold), alt D8, 3-fold D10 (rounded), 3-fold D10 (pointed), 4-fold D10, 5-folded D10 (pointed), Optimal D11, alt D24 (snub)
Coming soon: D21, D22, D23, D50
Related dice: Concave D4, Concave D6, D3 Shell, D4 Shell, D6 Shell, D8 Shell.

D24 Sphere

This is a Truncated Sphere D24.
The underlying polyhedron is a deltoidal icositetrahedron.

The numbering proposed here is very classical (opposite faces sum to 25).
A less expensive version is available in Antique Bronze Glossy with an alternative numbering here.

Available Truncated Sphere Dice: D4, D6, D8, D9, D10, D%, D11, D12, D14, D15, D16, D17, D18, D20, D24, D32, D33
Alternative shapes: alt D8, 3-fold D10 (rounded), 3-fold D10 (pointed), 4-fold D10, 5-folded D10 (pointed)
Coming soon: D22, D50
Related dice: Concave D4, Concave D6, D4 Shell, D8 Shell.

Truncated Sphere D33 Frosted Edition

This is the Frosted Edition of the 33-sided die specially designed to be the 33333rd entry of Kevin Cook's dice collection.
This die has a diameter of 20 mm and a wall thickness of 1 mm only.
It should contain the white wax used as support material.

The numbering has been carefully studied.
All numbers are by groups of 3 that sum to 51:
 - the 3 numbers at the North and South pole
 - the 9 numbers at the equator and at the 2 tropic taken 3 by 3 (any 3 numbers at 120°)
All numbers sum to 34 by group of 2 (except obviously 17, since only 17 itself can sum to 17 to give 34):
 - all the numbers of the poles and of the tropics with their symmetric number relatively to the equator
 - all the numbers of the equator (except 17) with their symmetic number relatively at number 17
 

This is Shapeways community member Henryseg's solution of D24 numbering with all group of 4 numbers summing to 50. Moreover the faces around triangular area sum to 37 or 38.
See this post for more informations.

This version will be available for a very limited amount of time with a very small markup: $25.00  instead of $31.99 (including VAT) in Antique Bronze Glossy (that's more than 20% discount).

The regular D24 is also available in a wider range of materials.