Whats the best way to store the boxes from the sets you have built/on display? Flattened? Or just break the seals on one end and store them assembled?

It's all personal preference.... I store them flat. If it's the break-open tab type box, sometimes I recycle them since they don't flatten. Many keep the box in it's perfect squaredness but I just don't have the space for that.

I honestly don't know why I keep so many boxes of my personal sets that I'll never sell...

I know it's an old thread but thought best to bump rather than start a new one.

I store my standard built sets with boxes flattened, instructions stored in a box file and spare parts bagged, labelled and stored away.

However I'm wondering if doing this with my UCS sets boxes would devalue them if selling in the future. Obviously sets with inner boxes of leave as is bit would the others be OK? Looking for the opinions of those who buy second hand UCS sets.