: It might describe paper that is exceptionally thick, opaque, or non-porous.

: If the video is a digital recording of a design program (like Blender or CAD), it might refer to a "solid" object textured to look like paper.

: If the video is a tutorial, it likely refers to heavy-duty cardstock or "solid" colored paper used for origami or modeling.

Since this file name looks like a personal or local recording, I don't have access to its contents. Would you like to in the video or clarify if you're looking for a specific type of heavyweight paper for a project?