The pdf envelope templates in the links fit standard business size envelopes (108 x 235 mm) available in Thailand.
Standard business envelopes available in Thailand (108 x 235 mm) are a bit smaller than the USA #10 size. These templates are sized to fit the standard business envelopes available in Thailand.
The pdf file size is #10 envelope, so to fit the standard business envelopes available in Thailand, there is a wider margin on the left, as you can see. Although the pdf file size is #10 envelope, it works best for us to print onto A4 paper, cut out the printing to fit the envelope, then paste the printed part onto the front of the envelope using a glue stick.
NOTE! USPS wants the bar code up against the top edge of the envelope -- within 1/8"
You can type or paste in your From abroad address and the To address to which you are sending the ballot or FPCA. Note that if you open the file in your browser, it is unlikely your browser will allow you to type or paste in the addresses. You should save the pdf to your hard drive, then open the file on your hard drive with Adobe Acrobat Reader. Then you can type or paste in the addresses.
After the addresses are in there, hit Print. From the Adobe Acrobat Reader print dialog, it helps to choose "Actual Size" and Landscape mode.