Folders, books and the main opening
Large folders and books can dictate the usable interior more strongly than soft belongings do. Compare their dimensions with the Foundation's current measurements and opening. If you carry lunch or clothing as well, check how those items occupy the remaining room without making the things you need during class awkward to retrieve.
Foundation 38L versus Prime 37L
Gather the same specifications for both models: interior layout, exterior dimensions, device provisions, and harness adjustment. The catalog titles do not establish which is more protective or comfortable. Selecting from comparable information is especially helpful here because a one-liter difference is too small to explain how either bag will work for your actual load.
