HOW TO MAKE A MAT POSE FILE
First of all, i assume you have already saved your .mc6 file (in the material tab, click on the + in the library, you'll have to choose if you want to save as a single material, or a collection). You can have a general view of all Poser file extensions at www.kuroyumes-developmentzone.com.
All you will need is... a text editor! (simple, isn't it?).
Make sure you make a backup of your mc6 file!!
Then open it with your text editor. You'll have this:
The trick now is very very simple. You only have to change the words "mtlCollection" into "figure":
Then, you save (not save as, only save, that's why i asked you to make a backup). Now, you only have to change the .mc6 extension of your file into .pz2 extension, and to put it into your Pose folder. That's all!!!
MAT POSE FOR A PROP
It's exactly the very same thing as for a figure, except that instead of "figure", you have to precise the name of the prop:
Even better if you have several same props:
Then you don't have to deal with name changes when adding a prop named the same.
CHANGING VERSION NUMBER
In order to have your files working with previous versions of Poser without that annoying message, just change the version number into the one you want to use your file in:
The version numbers you see in these examples are for compatibility. If you want your files to be compatible with Poser4, change the version number to 4.01.