Not yet reviewed by Pith; the record is open.

Heavy long-lived quarks, i.e. charm and bottom, are frequently studied both as tests of QCD and as probes for other physics aspects within and beyond the standard model. The long life-time implies that charm and bottom hadrons are formed and observed. This hadronization process cannot be studied in isolation, but depends on the production environment. Within the framework of the string model, a major effect is the drag from the other end of the string that the c/b quark belongs to. In extreme cases, a small-mass string can collapse to a single hadron, thereby giving a non-universal flavour composition to the produced hadrons. We here develop and present a detailed model for the charm/bottom hadronization process, involving the various aspects of string fragmentation and collapse, and put it in the context of several heavy-flavour production sources. Applications are presented from fixed-target to LHC energies.