"Deep scratches" refers to marks or cuts that are made on a surface, usually by a sharp or rough object, which go below the surface and can be clearly seen or felt. Full definition
You'll also want to fill any holes or deep scratches with wood filler and remove all the hardware. (dahliasanddimes.com)
Their nails can be trimmed frequently to keep claws blunt and unlikely to snag carpet or leave deep scratch marks. (littlebigcat.com)
While the earbuds have metal casing on the outside, I've noticed quite a few deep scratches on them, thanks to my slightly rough usage. (indianexpress.com)