I have had loads of people recently asking me how I can afford the postage, and how I send in so many swaps together and save postage sending multiple swaps... Well now, I am going to make a topic and reveal the secrets!
What im going to explain below, I can guarentee it works, and if you try to do it differently, or change anything, dont blame me if you get emails asking you to send in extra stamps etc etc.. I have sent thousands of swaps in, so I know what im talking about, dont question me about it.

(PS: If you have questions on how to do something, thats fine, What I mean when I say dont question me is tell me that what im saying is wrong, because its not!)
And now for the guide! ...
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Firstly, lets get it sorted about if one person buys several of your swaps..
This is pretty obvious, but for example, If you have 7 items up for sale, and the swapper 'Joey' buys 4 of your items, (even if your items are all different), you can send all of Joey's items in the same package!
So if Joey buys a pokemon card, a dvd, a ps2 game and a teddy bear from you, you can post them all in the same envelope/package - This saves you postage.
All you have to do is put all of Joey's items into your envelope, Write your member number on the front, and write every transaction number that Joey has bought. This is how it would look on the front:
If your only sending that one persons swaps, then write the address on the front of the envelope.
Now you have done that, you can stick the stamps to the BACK of the envelope. - Do not put your stamps inside, they can easily fall out when swapitshop open it as they are very small - Stick them to the back of your envelope - dont worry, Royal mail wont stamp them off!
If you only have 1 swap to send to one person, do the same thing, but just write the one transaction number instead of 4.
* --- Thanks for reading part one, and I hope you understand now about sending several swaps to the same swapper! --- *
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Now for sending multiple swaps, to DIFFERENT people, in the same Package.
- Yes, it IS Possible.
First of all, Ill give an example.
Lets say, ASC buys one of your swaps (a pokemon card), and Joey buys one of your swaps (a dvd), and I buy one of your swaps, a (PS2 game).
What you need to do, is package all 3 swaps up INDIVIDUALLY, so put ASC's in an envelope, Joeys in a different envelope, and mine in another envelope. When you have done that, add your member number and transaction number to EACH envelope, and one lot of stamps on the front of each envelope. (See figure 2)
Note: You do not need to add stamps to the back of each envelope.
When you have packaged all 3 swaps up individually, and added stamps, your member number, and transaction number, put ALL THREE Swaps into a larger envelope, and seal the envelope. On the front of the envelope you write your member number, 'transaction number: Swaps inside' and add a set of stamps to that package. (See figure 3)
Note: You dont need to add stamps to the back of the large package.
Now you've done that, take your package to the post office and send!
Intheory, depending on the swaps your sending, and how many your sending etc, Doing it this way SHOULD Save you postage.
The reason for this is because if you have a package thats 30g, and another one thats 50g, thats only 80g and you dont pay any extra on the big package as it would still be under 100g.
Hopefully this has helped, and you can now send multiple swaps!
If anyone still has any questions about multiple swaps, feel free to ask me!