Fdeck,
The link doesn't describe 3D printing of silicone. I don't think that can be done yet. They are 3D printing the patterns but using traditional rubber mold technology. I used to have a modelling business which involved this same kind of work. It isn't all that hard to do, but you need some equipment which you won't find just anywhere. First you make your pattern. You can use clay, plastic, 3D print it, or whatever, then you pour liquid silicone around it to make your mold. Then you cut open the mold and pour in more silicone or plastic resin. Both the silicone and the resin need to be "boiled" in a vacuum to remove any air and moisture which might get in during mixing, then you cure it under pressure and heat. The silicones I used would have good properties for an endpin tip, but the colors were white, pink, light blue, or even translucent, and I know of no pigments which can be added without degrading quality. Urethane resins come in almost any hardness and can be tinted, but the softer ones might not be tear resistant enough. If there is a university nearby with a big art department perhaps you could find a grad student with access to the gear and materials needed to do this and for an acceptable price. I doubt if you would want to pay what the pros would charge!
