I read some info a while ago as to why Paperboard Scratchers help to ‘save’ furniture.
Cat’s like to mark their territory and when they scratch furniture their claws secrete a scent which makes them return.
When cats smell the paperboard it has the scent of the trees and reminds them of the outdoors, as the paperboard is made from trees. As you know, cats have an incredible sense of smell and they relate to the paperboard scratchers which gives them a sense of wellbeing when they are either scratching or sleeping on it.
The corrugated cardboard helps keep in the warmth in winter and is cooling in summer….so they really are an ‘enrichment’ functional piece of furniture for your cats well being.
They then return to the scratchers and leave your furniture alone.