I just bought some shaped postcards online. They were listed as 143mm x 93mm, but when I got them, the actual cards were smaller than those dimensions…
The minimum size postcard that Canada Post will mail is 140mm x 90mm, meaning that if I want to mail these cards, I will have to do so in an envelope. Some of them are quite small. One is 70mm x 85mm, for example.
How do you deal with cards that are too small to mail? Do you send them in envelopes in official swaps and/or forum swaps or do you repurpose them for other things?
My first inclination would be to include them as extras alongside a postcard in an envelope, either for swaps or officials, if they happen to match the recipient’s interests.
Depending on how thick the paper is, and if you’re feeling crafty, you could also use them in a collage–maybe for a handmade swap.
You could also save them for holidays and birthdays, and use them as gift tags! All you would need is a hole punch and some pretty ribbon.
I was thinking about offering two or three smaller cards in exchange for one regular card in direct swaps or offer tags on the forums (with the caveat that they will be sent in an envelope), but I was pretty stuck on how to handle officials. Extras are a lovely idea!
Some of them would be great for gift tags and I think the smaller ones might look nice on a collage card. The paper quality is quite nice considering how small some of the card are.
You can stick them on normal sized cards with washitape and send them that way.
I have done this several times and it works very well.
The recipient only has to remove the tape carefully.
Wow!!! These are really cool. I’m always on the lookout for such shaped postcards but they are hard to get.
@Bille Didn’t know that this works. In the end the recipient receives two cards. May I ask you again for more detailed instructions, in case I will do this?
I have similar cards and so far I haven’t had an issue with sending them out as is, but maybe I should do what Bille does and make it easier for the postal system to handle them!
Thanks for great ideas. I have this same issue with a batch I bought from China. I’d tell you who the manufacturer is, but all the packaging is not in English. So here’s a pic of the box.
Same problem here in Poland - the post won’t deliver anything smaller than 9x14 cm.
Easy way out, I’d say, would be sending in an envelope. But once what I did was sticking on a frame made from cardboard to two sides of the card to make it bigger. I used border pieces from stamp sheets to attach the frame to the postcard - these should be easy to remove
About the topic, if the cards are to small to mail as postcard, they don’t turn into postcards if they are put inside of an envelope.
I suggest using those as gift tags, write small notes, part in a swap, decoration etc
Because, remember, even when postcrossing card is sent in an envelope, it must contain a postcard. To me these are just big die cuts (yes, some has “postcard” written in them but that’s not enough to make it postcard
I sent this card in an envelope to the UK, but I have also sent this card naked to the USA and it arrived safely. I’d estimate this card is around half the size of a normal postcard (10x15 cm).
The Portuguese Post Office has proper sizes for a normal shipment. There is even a model on that. If the postcard or envelope surpass or is under the standard, extra postage has to be paid.
If the postcard is a bit smaller than 10x15, I do not care, but if it is much bigger I do not appreciate sincerely. Personal issues.
Francisco
In the end the recipient receives two cards. May I ask you again for more detailed instructions, in case I will do this? 
I’d estimate this card is around half the size of a normal postcard (10x15 cm).