A sealed LEGO set is cardboard, print, and a seal. Built, it is something to play with. Throwing both into one list makes the damage unreadable. In the overview Security for collectors, LEGO is the example where the packaging can be the value.

What breaks without a thief

Cellar damp warps the cardboard. A stack that is too high pushes the corners in. Sun bleaches the yellow of the print. You store it dry, in the dark, with little pressure, not directly on the concrete. A set whose seal you open, you record as open from then on.

When someone comes

Full sets are easy to recognize and have a known shop price. Rare old sets have a collector price above that. They do not stand as a wall of original boxes in the room that faces the street. The rare boxes move to the inconspicuous place. Built models are bulky. A thief takes the box rather than the spaceship on the shelf, unless the spaceship is small and within reach.

The folder

Set number, sealed or open, condition of the corners, receipt for the expensive numbers. A photo of the seal edge. You count the built collection roughly by liters or by shelves, the sealed one number by number.