This article examines the practice of Rorschach testing as it was applied in a Dutch reform school for girls in the mid-20th century. Considering the assessment technique of Rorschach testing as an "examination" in the Foucauldian sense, this article investigates what type of identity was brought into being for the girls who were tested. Inspired by the praxiographic approach to trace the practices involved in testing, it shows that the Rorschach enacted a wholly new conception of the delinquent girl. Through the test, the reform school pupils were conceptualized as individuals with a literal inner realm, populated with drives, complexes and neuroses, which were said to shape their misbehavior. This notion of interiority was, strikingly enough, a rhetorical construction on the part of the psychologist, but was also produced as a reality in the practices surrounding the test. The article argues that, in the reform school, Rorschach testing not only served to assess the pupils' reeducability-a lesser known application of the Rorschach, particular to this reformatory context-but also served to govern them, precisely through its enactment of interiority. Through the practices of the test, a situation was created that suggested that the psychologist knew something about the girl that she herself did not; it was the creation of this "secret"-which forced pupils to look inside themselves-that placed the psychologist in a position of power. Utilizing the underused source of test reports, the article explores an application of Rorschach testing that has received little attention, further highlighting the test's versatility and power.