It is difficult for me to refrain from becoming a bit sarcastic here as your story sounds like a tabloid exposure. I will remain a sceptic until I see peer review publication. >, Use of Mercator in a cartographic educational sense is OK, certainly in demonstration of its distortion and rhumb lines. At the moment I can't think of any practical application of rhumb lines except in large-scale manual navigation. As for conformity, its application is limited to large-scale cadastral mapping. Conformity is a concept which only applies to the infinitesimal region about a point. At a distance distortion is quickly apparent and eventually becomes extreme. Conformal projection for global presentations is most useful to demonstrate the limitation of conformal projections. As for the Peter's projection (a perverse use of the well known cylindrical equal area) it has been severely criticized by well know cartographers. There are reasons for picking certain projections but in general, my basic recommendation is one of the equal area systems which preserve the concept of region size. There are also some good small scale projections which minimize overall distortion but are neither conformal nor equal area. >, the boundary is but what do you do with it. My mapping as been purely vector so the effect of the edges more easily handled than the fill problem. The proj library does indicate when points are out of bounds. In some cases it would be very difficult to provide an analytic function defining the projection boundary and the nature of this function will mathematically. Even if the function is known, the determination of the intersect with the limiting function and the vector is just about as complicated as determining the intersection by using the projection itself. Lastly, like the cadastral people supply their addenda to meet their need, the datum conversion group add their addenda, then why shouldn't the graphic types do the same. <,deleted material>, >, Source.