Does Chi Hardened Skin stack with DR from Armor spell?

[thom]

I always figured it did, but I wanted to make sure for my upcoming Fantasy Japan campaign.

I've created a Chi-based DR, assuming most characters would not be wearing armor in this time period. But, assuming the Armor spell exists, one of my PC's is sure to ask this question! ;)

For that matter would a Chi-based DR ability stack with armor in general? Thanks for any input!