Received a wedding invitation without a response card, which I understand was the norm until relatively recently. I have never been in this situation, so I googled it and got conflicting info. So I'm going to defer to your advice.
I know I need to reply with a handwritten note, and that's not an issue. Is a notecard formal enough? Should it be a plain white/ecru notecard? I have these:http://www.crane.com/crnImages/RF1405/Zoom-V1-RF1405.jpg
for everyday use, not sure whether they are too
informal for this. I also read somewhere that I should reply on my "personal stationery," or, failing that, plain note paper.
If it matters, another page I read said something like "If you received an invitation without a response card, it was probably plain white engraved in black, for a very formal event" and it is none of these things. The invitations are nice, but appropriate for a daytime event, nothing overly formal.