I want to be able to create text with double stacked accents but the normal fonts (Angsana, Cordia etc) don't seem to be able to do it. Maybe I'm not using the right technique when entering the characters or is it that there is a particular font for handling this?

ต์้ this is with character map

ใหม่จัดจั้งขี้น this is with keyboard and Windows 7

I know not exactly something you have in the jpg, but stacked I believe. What OS are you using?

I don't type in Thai so sorry it isn't exactly right. What I did is select the character, then the first part of the stack, then the second (higher) part of the stack. I used Angsana (new). Also, I sometimes have a problem with the correct character or accent showing when I paste from a clipboard to a browser.

MSPain

It should work with those fonts.

What operating system are you using? Have you set it up to use Thai language properly?

Are you doing this for web design? There are well-known problems with many fonts in webkit-based browsers (Safari, Chrome, etc.) which the developers are most reluctant to fix.