No idea on the rights to these images sonif you plan to do anything other that good with them I’d suggest reading the rights pages carefully… buuut:
I chose one at randomish and did this:
With a sharper light angle, more detail emerges…
I may have pushed the size a bit small, there’s some barely illegible text here:
and here… (sorry about the rotation, in a hurry.)
Beware that lots of these posters are pretty inappropriate by today’s standards. Kiss me Kate poster in particular, Oof.
Original image of the one I did, chosen largely because it had a simple-ish layout and a clear subject that has decent contrast from its background, which works well for engraves in the 6" or smaller category: https://hrc.contentdm.oclc.org/digital/collection/p15878coll84/id/460/rec/14)
Edit to the edit to the edit: I went “up” a level on that site, and wow their other collections are also great. The circus posters are really cool, lots of ephemera there.