Here’s one from me Brian, also this belongs to rendering and material handling…
Since V5 Rhino offers a UV Editor which lacks the most fundamental functionality of such a tool…that applies in particular to any 3d package which offers rendering but no native texture editing or 3D-painting:
That is Export of the UV-Mesh to Image Editors.
At this stage the UV-Editor is kind of like a can of Soda without a pull…How may one access what if offers?
I personally rarely do texture work directly inside Rhino but I once recorded a tutorial and wrote a very crude Macro which brings stuff to Photoshop as shown in the animated gif. Individual mesh islands get random colours assigned: That way one may quickly mask and distribute part of the model to layers. It can not be hard to add this functionality as a proper command.
In case you are unsure as to why bringing flat UV meshes to Image Editors may at all be useful please watch the Youtube clip linked above.
Edit: The screen recording looked good but the resulting animated gif could have caused epileptic seizures, exchanged. Here’s btw. a Discourse discussion by users who miss that feature too…