I have a few kitless pen blanks made with alumilite clear slow resin cast in a bespoke mold from ptownsubbie. They range from translucent to transparent with swirls. These are excellent demonstrator fountain pens, asking $15 each plus priority shipping. If you're interested in more pictures...
Where does one find clear tubes for casting pens blanks? I have been using Ptown subbie silicone molds and pvc, but I have seen clear tubes on some videos.