how can i hang frames with no hooks on the back?

hi! i've been trying to figure out how i can hang these frames in a gallery wall i'm planning. they don't have any hanging hardware on the back, and all of the solutions i've seen online won't work for these frames as i can't drill or nail anything into them (the first frame is some sort of terracotta/ceramic, the fourth one is metal, and the others are all thin plastic). i'm considering attaching sawtooth hangers with epoxy glue, but i'm not sure whether that would work. does anyone have any suggestions as to how i can hang them? thank you 🙂