Item made up of items

I am trying to create an item that contains several items. For instance: the item of a specific book is made up of five items inside it, which are the five illustrations I will attach as archives. I could do it as a collection, but then it would not show up as an item when navigating by items. I can also use the Item relation plugin, but the result is not exactly what I want. Any suggestions?

Composite objects are a tricky thing in Omeka. Item Relations gets to many cases.

Could you tell more about what exactly you want?