The penal colonies were modern experiments that attempted to resolve surplus British populations, achieve strategic and naval ambitions, and form new imperial markets. Metropolitan reformers were keenly interested in prison systems, writing speculative accounts and plans in response to early evidence from New South Wales. This chapter analyses major theories about the penal colonies and ‘systematic colonization’ by Jeremy Bentham and Edward Gibbon Wakefield, examining how evidence was drawn from colonial texts and repurposed for metropolitan interests. Alternative forms of information from the colonies were fed into metropolitan inquiries by the Quaker travellers James Backhouse and George Washington Walker. Quasi-official colonial experiments with convicts and prison reform trialled through the first half of the nineteenth century in many cases anticipated the prison reform underway in Britain. This chapter analyses the network of texts that brought metropolitan attention to bear on controversial aspects of convict transportation and colonial reform that reshaped ideas about society, crime, and punishment, with distinctive religious overtones, and how new models for reform emerged from colonial experiments.