Although padded milers are more expensive your seeds will not be reduced to dust by the automated sorting machines. I have had this happen on more than one occasion and it's a real bummer.

Whoa ... that is so cool, thank you.

We run into this situation at work when we do invitations for certain events. Since the wording on the inside of the invitation is done on the computer, I use two versions. The following is a little formal, but you can tailor it to your own needs: for singles: "May we cordially invite you to...."; and for those who have significant others: "May we cordially invite you and your guest to..."

I don't really like the balloon idea. They are a big choking hazard and although your girl may be big enough, a smaller child could get a hold of the balloon and I doubt the adults there would even be aware that ballons are choking hazards. The ideas they provided you with are the probably the best to go with. I can't really think of anything else that would be suitable and flat enough for an envelope. Maybe cartoon bandaids or something... but again, do they even have water to wash wounds, would kids try to chew the bandaids not knowing what they are, etc? Stick to what they recommend or close variations; thay are probably tried and true favorites You don't want to open a can of worms introducing a new item into a culture that isn't used to it.