Been doing the 3D Wings part and it seemes I can not get it right...

If I want to save my work I have done so far in wings and close down the wings program to come back later to continue, in what format do I have to save the file?

Tried to save in wings format after I moved the vase to the central point and just before preparing for texture mapping. When opened the file again and start the adding new material by different colors, the colors are not showing on the vase.

*Found out I need to have Show Materials checked in the View menu* Sorry