I have shipped large quantities of the same size print, usually in used paper boxes, then within another box. Both FedeX and UPS will do double boxing if you turn up at a store. It is a lot cheaper if you have a business account with them, maybe a third of the usual rate.
17" x 22" probably doesn't count as over-sized. 24" x 36" definitely does, when double boxed.
For really important prints, going to archival departments at universities, I will sometimes use a sheet of plywood or corrugated plastic as a stiffener. You really want to avoid corners getting dented in.
(About one of three packs of 24” x 36” sheets, from paper suppliers, arrive at my studio with dented corners. They go straight back, but it is a hassle, especially if you are trying to keep stockpiles lean. Hahnemühle’s packing is particularly poor, Canson less so.)
Brian A