Custom Materials

How do you make or add custom materials to the materials library, I tried duplicating and edit but I can not change the name of the duplicated material so I cancel out. Tried drag and drop that does not work and there no add button.

These could be bugs, but is also likely early/unrefined UI. At the moment, the way to do it is to drag a material from the Standard Materials library into the Model Materials and then edit it. Alternatively, you can duplicate materials already in the Model Material library by right-clicking on them. If neither of these is working, then there’s likely a bug (ok, a bug or two). That said, there probably ought to be an add button in the Model Materials that creates a new matte-grey opaque material in the model so that it can be edited. I’ve logged this in MR-1590…Is that along the lines of what you were thinking?

Thanks Dan that’s what I was trying to find out.

My problem is this:
From Rhino 7 I opened a Rhino 5 file which had numerous custom materials located in a folder on my hard drive. The Rhino 7 file displays the NAMES of the materials in the materials panel, but only displays a solid blue or white flat image in render mode.
How do I add my custom materials to the accessible render materials library?