Cheongju's booking detail lists a free stamp-making class on Saturday, October 31, 2026, 10:00–12:30 at the Early Printing Museum, 713 Jikji-daero, Heungdeok-gu. Adults register online from October 17 at 09:00 until October 30 at 23:59, first come first served. The reservation table gives 16 places, while the descriptive paragraph says 15 per session; confirm the current capacity on the booking screen.