I'm pretty sure they'll be able to go as a large letter, hopefully regardless of the quantity purchased. I'll offer the choice of standard 2nd class or second class signed for, for those in the UK. I don't really want to give first class and first class signed for as options, as it increases my chances of getting confused! I'll contact those further afield separately. Now I've got them, I'll figure out the best packaging to use - I'm thinking just a regular paper envelope might be sufficient; it will keep the cost down and is fairly eco-friendly (note that they are not individually wrapped). Once I've figured it out, I'll post a total cost for each postage option and people can Paypal me for whichever option they prefer. I think they'll have to go over the PO counter, as I guess that's the only way I'll get proof of posting.
Not sure if I should post my Paypal email on here? Maybe I just need to send a group PM?