I love when things turn out exactly as I had pictured them. This one was a little iffy, all the way until it was finished. It turned out much girlier than I anticipated, but so far DJ does not seem to mind. The moss and girliness makes me think of Frances Hodgson Burnett's The Secret Garden.
I ordered moss on eBay, with no idea what the color or texture might be - or even quantity. I'd recommend the seller I used, although he never did respond to my questions before buying. But it was delivered quickly and packed well.
Quick note on moss: I ordered the dyed green variety, and it is a perfect forest/hunter green. The natural moss would be better for a silvery or sage-y color scheme. It's hard to say exactly what the coverage of a box of moss is, but I used about 1/3 of a box for the bulletin board.
The base is a (thrifted!) bulletin board, the frame painted with pewter-y art paint. I attached the moss using little dots of hot glue. Not too many and not too close together, because I was afraid that too much glue would make it hard for the corsage pins to hold. The moss sort of sticks together on its own, so I didn't need a ton of glue.
That's one of the escord card envelopes, tacked on there with a pearl-headed corsage pin. I went a little embellishment crazy with silk flowers and ribbon. There's a trick to the flowers. Pop the heads off the stems, then insert the head of a sewing pin into the hole left by the stem. Instant flower on a pin. (Yes, I'm sort of embarrassed about the state of our dining/crafting table. I'm a terrible housekeeper.)
The whole thing is sitting on a 12" plate stand from Michaels. It's pretty stable, but if you're trying to fit more than 40 cards then two boards would be better.