I wouldn’t say it’s a surprise, many Hittite texts describe hieroglyphs drawn in ink, and you have development in monumental writing that shows influence from cursive drawing. But it’s nice to see some physical evidence :-)

It was new to me! As a non-Hittitologist all I knew was that actually preserved non-monumental media was pretty rare--as I recall almost all we had was a few lead strips, right? But that's a good point--where are some good discussions of the evidence for non-lapidary Anatolian hieroglyphic media?