door Rules are rules, and glass cannot just be sent by post. So is glitter, which used to be made from ground glass (nowadays, plastic is used for this).
Of course, it is not really strange that glass cannot just be sent (without proper packaging) by post. The mail sorter, the postman, they could of course injure themselves on this. Sending it openly can also damage other mail. In short: it is forbidden.
So the postcard pictured here has – if you look closely – glitter made of glass. The sender thought it could simply be sent (even without an envelope), but so the observant postal official thought otherwise.
The plan was to send the card from Amsterdam to Ginneken (near Breda). Sending of the card was cancelled, and the card was returned to the sender.
Apparently, this incident did not happen very often, because there was no standard label for it. A blank label was stuck on, with ‘Stamped glass/Not allowed’ written on it. In violet, a two-line stamp: ‘Postkantoor Amsterdam/Bureel vertrek’.
