How-To: Glass Klein Bottle
Dutch glass crasftman Ramon Vink runs a studio called Poelgeest Glass. Using modern lampworking techniques and tools, he makes scientific apparatus and artistic pieces like this Klein bottle, the forming of which he has documented in a series of five YouTube videos. The videos themselves are pretty raw, with minimal post-production and no narration, but taken altogether they do a good job of documenting not just the general process of forming a Klein bottle from stock glass tube, but the specific tools and skilled manipulations required for each operation.