In 1901, fingerprinting was first implemented by Scotland Yard for the purposes of criminal identification. Recording identity in the imprint left by a body’s digits allowed for the identification of individuals on a mass scale, ‘fixing’ their identity with apparently incontrovertible certainty. But in this essay it will be argued that the fingerprint also served as an example of a much more enigmatic and ‘impressionistic’ identity that was shared by the discourses of two contemporary figures - Sigmund Freud and Joseph Conrad. In the development of psychoanalysis, particularly around the turn of the twentieth century in texts such as Studies on Hysteria (1895) and The Interpretation of Dreams (1900), Freud continually utilised the notion of the ‘impression’ to articulate his ideas, promoting theories that had a profound effect on how identity could be conceptualised. Likewise, the novel Lord Jim (1900) serves as a prime example of Conrad’s Literary Impressionism: a style of writing self-consciously created as a response to a novelistic realism that failed to capture the essence of lived experience. In lifting prints, analyzing traces and reading impressions the discourses examined in this essay all display a dominating concern with the unintentional, the fragmentary and the imaginary, all of which had to be enhanced, analysed and represented by authoritative experts who could make the layman see true identity.