This article explores the multimodal assessment practices of teachers in a vocationally oriented filmmaking course, specifically identifying the principles guiding the assessment of students' post-production work. The study addresses the question, according to what principles do teachers assess students' film post-production choices and expressions? Although there is previous research into assessment of multimodal text across different subjects, it is yet not fully understood how multimodal assessment plays out in practice in vocationally oriented media education, where media artefacts (or 'products') become the ultimate expression of competence. Utilising a multimodal social semiotic framework, the qualitative analysis of teacher interviews, documents, and artefacts identifies four assessment principles: composition of text, text-making process, alignment with institution, and alignment with profession. Tensions emerge between the syllabus, emphasising practical/technical skills, and teachers' assessments, which also take into account aesthetic dimensions of filmmaking.