Keith,

You need to get something that is more specialized to growing orchids than a
general gardening publication.

The reason you don't want pine bark is that it breaks down too fast.

When you repot your plants you don't want to disturb them in a few months
later and do it again when the medium breaks down. Personally, I don't use
bark anymore except for a few specialized plants that like it on the wet
side.

I have switched to a cocohusk mixture with alifor (clay marbles). I find
this medium allows air to the roots which is essential because plants breath
through the roots. The coconut husk also does not compact in the pot
allowing the roots to penetrate the medium. Best of all the Cocohusk mix
lasts 2 to 3 times longer than bark mixes.

Good Growing,
Gene