The mesh lines are not what I was discussing. I prefer P6 to do textures, but on a mesh that is split front-back, it is difficult to do tan lines,etc. By drawing lines across the seam in different colors, it makes it easier to make the match, especially if this guide is a partially transparent layer, to be turned off for the final texture. To repeat advice that was given to me here: Take your model into UVMapper, save it as a single group with a different name and "aquire" the model in Painter 3D. If you want to live in P3D you will not need the guide lines, but the layer function is not nearly so robust as it is in P6, or as I understand it PSP or PS.