I have fed some geometry with a Material (texture map) in to a Copy node and then checked Pack and instance.

This stops the material from being renderable. Is there a way to retain the packed state and still render the Material on the geometry?

You might be confusing renderable with viewport display.
Which render engine are you using?

I am using Mantra (Houdini v18.5). It does not render a Material if I use a Duplicate node or a Copy to Points node and check "pack and instance".

I found the issue: In Mantra ROP you must set Rendering tab-Render tab-Declare Materials: Save All Materials and Shaders

on your Mantra set Rendering/Render/Declare Materials to Declare All materials and Shaders (or just materials if you are not using any shaders directly)

Thanks, I discovered that