Different Doom shirt versions from id

I have asked Pat this, but he is either doing the "I'm from the official id team and will not say ANYTHING to anybody" thing or just hasn't read it.

But I would like to know this about the Doom tee shirts a friend and I ordered from id back in December.

Mine has a newer style id logo (green, and rusted looking) on the back and his has the old blue and yellow one from the original 90s Doom games and shirts.

What's up with that?

I want one or a few of those T-shirts :(

I've had two of the new-logo ones, and one of the older logo. I'm going to guess they just kinda switched partway through.