Laboratory measurements of room temperature glass flow do show a motion consistent with a material viscosity on the order of 1017–1018 Pa s.Although the atomic structure of glass shares characteristics of the structure in a supercooled liquid, glass tends to behave as a solid below its glass transition temperature.
Naziv steklo se kljub temu pogosto uporablja za opis katerekoli amorfne snovi, ki ima temperaturo steklastega prehoda Tg.