How to Romanize Thai or Lao

"It is very hard to make a good Romanization with lots of vowels. It just has nine simple vowels and no real diphthongs because glides are consonants, but I'm not sure how I'm going to represent all of those vowels," he says. "With this many vowels, it looks like you kind of need a combination of vowels sometimes." He uses digraphs or lots of diachritics in some cases.