i used 5/8'' cc ply, i bought a couple bunks of old stock from the big box store, they had on sale, used it every where,
i'd run it horizontally, screw it or nail it, what ever works for you, easy to add a block if stud off center, break vertical joints ,min of 24 to 32 inches, pending stud spacing, nail edges o screw then at 8'' on edges and 12 to 8'' in field.
i tacked my on with gun nails then went back and installed 1-5/8s screws.
if hanging and unsure if ply will hold make a cleat large enough to grab a couple studs., its amaze you the strength you will gain, even french cleat can work,
good luck nothing like a solid wall shop, with ply, can attach what you want where you want, my experience with osb is it sometimes won't hold a screw well.
Rj in az]