School uniforms are proliferating as a staple in figurations created of successful students around the world. In Australia the uniform as compulsory formal school wear is a growing phenomenon in both public and private education sectors. School uniforms have often been adopted as unproblematic, by schools, parents, policymakers, and students themselves. It remains unclear from the previous limited and often contradictory research, precisely how uniforms materially affect student academic and social outcomes. Research that considers how students themselves not just perceive but "feel" about their uniforms is scarce. I focus on the affective response of students to their school uniforms at one government co-educational selective science high school. A PhEmaterialist approach deprivileges human agency, accounting for matter as dynamic, affective and of consequence in activities, performances, and events. The school uniform as matter is explored as a dynamic and powerful affective force in education and is situated as an integral part of a school's iteration of binary gender differentiations. Uniforms matter twofold, as a conception that materializes what matters and the differential affect on the bodies that wear them. Bodies respond affectively to the uniform with a sense of comfort or discomfort, consciously and unconsciously. Bodies that do not fit easily with the required uniform hurt as students undergo everyday activities at school. This paper considers the affect of the uniform, with a filmic response from one high achieving 'smart' girl through a fine-grain analysis of her feelings of belonging and dis/comfort "with" and through her school uniform.