PETG is the glycol-modified copolyester of poly(ethylene terephthalate), in which part of the ethylene glycol is replaced by cyclohexanedimethanol, suppressing crystallisation and keeping the material transparent and melt-processable [1]. In stretched miscible blends with polyethylene naphthalate, PETG reshapes the crystallization behaviour of the stiffer partner [1]. As a reusable and biocompatible substrate it serves cell culture, an unexpected role for a packaging polyester [2]. Blending PETG with thermoplastic polyurethane yields 4D-printable shape memory parts [3]. Recycled PETG fed into additive manufacturing has been examined as a feasibility study for circular material loops [4].