I am using Poser 5, and am interested in releasing some items to (hopefully) be used with both poser 4 and 5. My props (pp2 files) have references to materials (mine) which seem to be P5 specific (node). Is there a way to create props with material references that are backward compatible, thus requiring the same product for both versions of poser? Does P4 simply ignore parts of the pp2 that don't make sense to it, or does is really hate that? Your thoughts are appreciated!

Unfortunately, not without hacking the CR2. HOWEVER... As long as you don't use any nodes except 2D textures, and only use them on the Texture, Reflection, Bump, and Transparency bits, with the color swatches only on the Diffuse, Highlight, Reflection, and Ambient bits, they open in P4 just fine. The big problem here isn't so much the material nodes. It's the lack of an rsr thumbnail in the library. I'd also reccomend making sure you put the obj in a subfolder of the Geometries folder, and point the CR2 to it... P5 and PPP tend to put the geometry in the character folder, and that iritates many people, who never put the CR2 in the default folder anyway, having created their own filing systems.

Poser 4 does tend to ignore the parts it doesn't understand. But it's not a bad idea to pull the P5-specific data out anyway, if it isn't being used. It'll result in smaller file sizes, at the very least. Download a few items from Free Stuff and study them to see what does and doesn't belong in a P4 file.

If you decide to edit the files, remember to change the version numbers so no one gets that annoying "newer version than expected" message.

You can convert P5's .png thumbnails to P4's proprietary .rsr format with yarp's P3dO Explorer utility (available in Free Stuff and at SENO Software).