Playmobil cargo holder for cardboard

My son wanted more cargo for his Playmobil trains and trucks. I made this little holder that holds 10 sheets of cardboard. And now it looks like he transports concrete floor spans. 

If you cut your cardboard strips to a length of 25cm and a width of 7.5cm you have enough room. But try one first. Too wide and you will have a hell of a time to get all the strips in and might break a holder. Like I did. 

The little points on the bottom slot nicely in the train carts and the cargo can be lifted with the Playmobil Harbor Crane.