By “submittals” do you mean what kind of files do you hand off? If that’s the case it depends how detailed your housing is. Generally tight Illustrator drawings will suffice, but if there are particularly complex surfaces and/or details you may need a 3d model. Something as simple as a headphone case, for example, can be sampled from Illustrator drawings. A complex shoe midsole may need a 3d model. It may also depend on the sampling capabilities of your vendor.