These pens have been on my Amazon Wishlist FOREVER. I recently saw a Youtube Video from Banana Peppers(nee Graveyard Girl) look at a similar product and decided to bite the bullet and buy them on Amazon. I expected them to work the same as the Marvy Snow Marker, for those outside the world of the snow marker, it's a pump felt based paint marker that puffs up in the presence of a heat tool.
So I did the next best logical thing and got to swatching:
For the heart stamp I used what was on my desk, Trinity Stamps Crafter's Heart. The pens are Korean and sold by the brand Dong-A. The pens have a smooth roller-ball and were not very hard to control compared to the snow marker that tends to flood the paper.
I used a Wagner heat gun and went a little crazy, as is visible from the toasty marks on some of them. If I did it again, I'd use my cheap heat gun that radiates a less vibrant spectrum. The more pigmented colors had a very consistent, stable restrained popcorn-ing. The light colors went delightfully mad.
The Marvy Snow Marker was a more marshmallow puff and different in texture than the Popcorn Pens.
While enjoyable, I don't immediately have plans for them, but it's always nice to have something in your craft arsenal, just in case a popcorn based pen emergency happens.