De nada

Thank you very much osiris!!
Your explanation is fantastic.

Hola Diora Your English is very good

Well you can send any envelope size you wish, but obviously larger envelopes will cost more in postage. You can send either A5 (half of A4, sometimes called "C5") or A4 (can be called C4) or any other if you wish, especially if you're sending the photos to be signed.

If you are requesting a photo from the celebrity, you limit the photo you can receive by the envelope you send (if a celebrity only sends out 10x8 photos, they will not fit in a C5 envelope). It is best to check previous successes to see what photos a celebrity will send.

You can save on postage by folding your SASE, and putting it inside an envelope of the same size (i.e. a C5 envelope folded inside another C5 envelope).

Most fanmailers, I believe, send C5 envelopes, as these will fit 6x4 or 7x5 photos easily, but those sending 8x10s send C4.

By the way, the reason the envelope is slightly larger than A4 is because obviously the paper has to fit inside it, so they make them a little larger than the paper So a C5 envelope will fit A5 paper in it (this is the reason for the different names).

Hello!!Sorry for my english, i'm Spanish.
I want to send my first fanmail and I don't know if to send a SAE that measures a half of an A4, in a envelope that measures a litter more than an A4(in the shop they said me the envolope is A4 size, but it is bigger than an A4 paper), or use an envelope that measureses a half of an A4 and to fold the SAE in it.
Is the A4 envelope so big?or not?

Thanks!!