This is a set of loaded dice intended for 3D printing. Each dice type has a neutral, loaded to 1, and loaded to the highest number version. The way they are weighted is by including internal structures in the 3D model to force the printer to fill in the area behind a face with a higher infill (80 to 90%). Because of this, when printing, the amount they are weighted can be adjusted based on the infil you chose for the print, with the less infill increase the amount they are weighted.

Bear in mind that this method of weighting dice is only increasing the likelihood of a face and gets less and less effected with higher face number dice. For example, in my testing of the d20 (weighted to roll 1s), I was only able to triple the amount of 1s rolled, bringing the likelihood of rolling a 1 from 5% to 15%.