I have been on a quest to find these markers since I discovered chalkboard labels on Pinterest about two months ago. I tried office supply stores, Michaels (as suggested by a blogger), Target (as suggested by another blogger), Archivers, and finally found them at Hobby Lobby (as suggested by a salesperson at Archivers).
It was getting ridiculous and yes, I could have ordered them on line but didn't want to spend $5 to ship something that cost $7 (I had a 40% coupon, so didn't pay the $11.99 price). I probably spent more in gas than that, but like I said, it had become a quest, and when I'm on a quest, I'm not always rational.
I was starting to worry that once I found them, they wouldn't live up to my expectations, but I'm happy to say, they were worth the effort.
So far I have used them to rewrite my chalkboard labels in my fridge (before I just used chalk and it wiped off too easily, and it's hard to write neatly with chalk), and to label the little whiteboard labels on my hanging organizer in the coat closet (previously done with dry erase markers - same problem with rubbing off easily).
The one thing I have noticed with the markers is that they do take a while to dry, but once the ink is dry they are pretty well set. The first ones I made smudged cause I touched them too soon, but once I let them dry they were fine. My daughter accidentally spilled milk in the fridge and got a couple wet, so those rubbed off, so I know they can be wet and rewritten.
Now I'm trying to think of other things I can do use them for, as I really like the way they look.