First, the binding on the card isn't as dark as it looks in the photo but it does have a strong contract. I was surprised that (almost) everyone preferred the look of the zigzag edge as I personally prefer the binding. I wanted to be able to do the zigzag well enough to use it in pinch. I'll probably continue to use both as well as try some other suggestions too.
The pen I used on the back of the first two was too thick and messy looking - I found one that writes with a thinner line AND I stayed further away from the edges when writing. I debated about NOT sending the first two I made but heck, the recipients will understand that I'm in a learning phase!
Mailing the first one was a challenge yesterday as he tried to tell me I had to mail it as a parcel (versus a letter). Luckily I was reusing Deb's envelope and was able to show him the stamp she'd used to mail hers. He also said that since it was in the clear envelope, it was not a "postcard" (I knew I couldn't use the same postage I'd use for a postcard ). We'll see if she gets it! (He did hand cancel it as I asked but told me it would go through the machine anyway saying "everything does".)
I printed some information from the site where Deb bought the envelopes that I plan to take with me next time.
Finally, for those of you interested in learning more about fabric postcards I found a site that has several tutorials listed. Thanks to Vicki and Deb for inspiring me to try these.