"How much scaling of the image can be done before you lose significant detail in the image?"... You can't lose any detail if you re-size upwards... In fact, if you use a decent app like Photoshop or PSP, resizing upwards smoothes out visible pixelations nicely. It's a matter of personal taste, but I often use resizing for this reason alone (Improves the perceived quality of printed images in my opinion!. This approach is also handy for texture maps... but I haven't experimented to find out what is the largest texture map usable by Poser. Give it a try and see if you like the results.