Foam Paper for DIY Grid Spot... Where/What kind?

I'd like to make a grid spot for my light ( tutorial can be found on this person's flickr http://www.flickr.com …e/sets/72157594​358068593/ ), but I'm not sure where and what kind of foam paper to get. The flash units get hot, so wouldn't foam melt?

That seems like an awful lot of work. I think cutting black straws would be much easier and give you the same results.

But I'm guessing a craft store or maybe even WalMart would have the foam paper.

Its corrugated plastic, same stuff used for political sings. You can find it at either a plastic supply company or a sign maker, or obtain one of those political signs. I've also seen these made of of regular corrugated cardboard.

Yeah, but the foam paper that is used to wrap the plastic int he shape of the flash head... won't it melt from the flash head's heat?

Oh, I see what your asking about now, I didn't read fully through that link before posting my last comment. I believe the material they are referring to is fun foam, however it goes by a lot of names, I think the term foam paper is deceptive cause there isn't any paper product attached, it basically just a foam sheet. I just took my soldering iron and tried to melt a scrap, although it did melt, it required a good amount of constant heat and even that didn't do too much. So unless your firing your strobe frequent enough to the point where you might damage the strobe itself, you should be fine.
BTW: The foam also does a fairly good job of cleaning off a soldering iron tip.

Awesome! Thanks!