The bigger the dice, the more detail we can add to your logo. D20's have about 5mm x 5mm of space in the center of the face to work with and no line can be thinner than 0.5mm. The d6 for example has about 10-12mm of space to work with so we can add a lot more to a D6 vs a D20.
*Current lead time for Logos is 2 weeks*