Quote - DG, 

I'm supposed to load the prop, go to WINDOWS=====>DOCUMENT WINDOW SIZE...

and make the size a square demension right? I'm trying to make 90 X 90 and the window resizes itself. Seems you cannot go under 120. And also when I make my document window a smaller size, the prop is totally out of sight.

All I do is this:

1. Load the item into the poser scene
2. Render Menu
3. Render Dimensions
4. Render to Exact Resolution
5. Uncheck Constrain aspect ration and then type in 91 x 91
6. OK
7. Render Menu
8. Render as you normally do. I usually do a P4 render as it's faster.

Your image will render at 91 x 91 pixels

Save it out as a .png   to the same folder that contains the .cr2, .pp2, .pz2 etc file that you want a thumbnail for.  Save it as the same name as the .cr2, .pp2, pz2 etc file. Voila! Thumbnail :)

Don't forget to change the size of your render dimensions when you want to render a regular scene :)

"It is good to see ourselves as others see us. Try as we may, we are never
able to know ourselves fully as we are, especially the evil side of us.
This we can do only if we are not angry with our critics but will take in good
heart whatever they might have to say." - Ghandi