What's the softest type/brand of ASPEN shavings?

I need to get some ASPEN shavings for my hedgehogs cage. He's on fleece liners, but I also want to put aspen in the cage to burrow in, because he doesn't like to dig in the fleece strips I gave him. Some brands are "pokier" then others. Which is the softest kind? I've heard snake aspen is soft.