Did you know that...
...you can export all Materials in the Scene into a single file, with the option of also copying all referenced textures to the new file's location:
1) choose to export as an .mxl (Maxwell for Rhino 4 Material Library) file:
2) choose to copy all referenced Textures:
3) choose to make all Texture paths relative to the new .mrl file:
4) choose or create a new folder, and Library name:
Process completed, you now have a single-file Material Library that may be imported into any new Scene in one operation, with the assurance that the imported Materials are exactly as they were in the Scene they were saved from.
Notes:
I have noticed that Rhino does not seem to set the 'current directory' correctly when opening a .3dm from the recent files list, near the bottom of the File menu. This causes the use of relative texture paths to fail. The apparent workaround is to always open a file using the File > Open method.
...to be continued...