Another option for texturing large models economically is to use asymmetrical seamlessly tiled images. And it's OK to also use a non-tiled image on the material, for example overlaying a displacement map giving rivets and weld seams on top of a tiled image of wrought iron.  Most of my models are too big to even consider using a single (non-tiled) map to texture the whole model.

     If you see a blurry smear on the model when rendered, but only in a few places,  it may not be due to small texture image size;  the model might have a highly acute (sliver or needle-shaped) triangle in the mesh.  These are notorious for causing UV mapping distortion.

     I seem to recall reading that P8/PP2010 can use maps of twice the resolution of earlier versions of Poser.  Can anyone either confirm or deny this?

Poser 12, in feet.  

OSes:  Win7Prox64, Win7Ultx64

Silo Pro 2.5.6 64bit, Vue Infinite 2014.7, Genetica 4.0 Studio, UV Mapper Pro, UV Layout Pro, PhotoImpact X3, GIF Animator 5