In this paper we define a model of literary prose text, in terms of an ontology: concepts, relations and rules. This ontology contains both concepts related to abstract linguistic entities and to material/geometric notions. Rules are included in order to modelize the conventions of orthotypographic tradition. Once the model established, we define “graphemic and graphetic methods” as transgressions to these rules and investigate the use of such methods in speculative fiction texts, based on a 20th-21st c. international corpus. We also investigate, whenever possible, to what extent and in what way graphemic and graphetic methods have been translated into and/or adapted to other languages.