I've you've got that many retainers... why not just organize them so each one carries specific types of things? That's what I did. I have my retainers divided up so if I need say... lumber, I know to always go to the retainer carrying lumber as no one else would have any unless I pulled it for a special project I hadn't finished yet. And I always make a note of those so I don't forget lol. I even have them split by tab so I know one tab will have raw mats, one will have lumber, etc.