Hi jewels1
It depends on the weight / shape / size of your envelope
1 international forever stamp costs $1.15. You can buy them here:
https://www.amazon.com/gp/product/B071V ... 1a3532aa62
1 international forever stamp = 1 once letter = 28 g letter
2 international forever stamps = 2 onces letter = 56 g letter
You can calculate the price (=number of stamps you need) here:
https://postcalc.usps.com/ 
USPS Postage Price Calculator
For example, if you live in Germany and you want to receive a letter from United States.
Then click, calculate price based on Shape and Size.
On the next page, enter 1 once (28 g) if your letter is under 1 once. Click "Letter".
On the next page, click "None of the following" for a normal envelope
The result for an envelope under 1 once (28 g): The cost is $1.15 = 1 international forever stamp
So if your self addressed envelope + your picture weight under 1 once / 28 grams put 1 international forever stamp on it.
Uploaded with
surfmypictures
The result for an envelope under 2 onces (56 g): The cost is $2.13 ~ 2 international forever stamp
The price for a First-Class Mail® International Large Envelope under 2 ounces (56 g) the price is $3.18 (~3 international forever stamps)
Fanmail
