Khmer style printed wedding invites are absolutely normal. The system is that the envelope that the card comes in, is used to place your money gift in it. At the wedding you leave the envelope and money with someone who sits by the door as you leave.
The red diamond print below is the really traditional
colours and the two almost kissing is the ubiquitous image. It was only to this wedding season (dry season Oct - April is time to marry) that I ever saw any colours or styles different to the mostly red print. Check out the pretty pink that is very modern!Envelopes look like this:
