How to create and keep new textures from an image?

Hi, Sometime ago I had succeeded in creating a texture from an image of a wooden object (the Wood textures in Sketchup, even Pro are very poor), but I don’t remember how I did it.

I thought it had perhaps been kept automatically in the materials, and that I had only to pick it up there, but it isn’t.

In my design I have some objects with that texture, but I may not apply it to other ones.

Isn’t there somewhere a bigger collection of textures that one may import?

Kind regards

No. You have to save the material(s) out to a collection. What version of SketchUp are you actually using? Your profile says you are using 2017 Make but you posted and mentioned SketchUp Pro.

You can either save your materials as a local collection via the Details menu.

Or if you have a collection already set up, you can open the secondary pane of the Materials panel and drag the thumbnail from In Model to the collection.
Screenshot - 4_29_2021 , 10_04_51 AM

Thank you very much! Myself I have Sketchup 2017, but I am actually on the Pro version of my daughter.