The renewal of school ID cards with an ISIC license (revalidation) is now done exclusively digitally; there is no visual revalidation with a hologram or thermal printing. More information about digital revalidation can be found on the ISIC website: https://www.isic.cz/en/article/extending-your-card-without-a-revalidation-sticker-how-it-works-and-where-it-s-possible
To renew the ISIC license, it is not necessary to visit the CTU Card Centre. The user extends the validity online via the self-service portal: https://card.cvut.cz