It's quite a recent one - it was in the exhibition that was on at the RA a couple of years ago. Huge IRL. Fantastic exhibition all together.
I am a big fan of Bridget Riley, but she doesn't seem to licence many posters. Hmm.
Anything here appeal?
There are quite a lot of local art fairs at this time of year - perhaps you could find an original artwork instead of a poster? I'm planning a trip to this one.