our cats seem to prefer a scratching post that I make over the carpeted ones. I take 2 x4's about 32 inches long then screw them together, to make the post, then screw that to a nice 3/4 plywood base after you cover the base with a thin low napp carpet piece. Also staple a piece of this carpet over the top of the post and down about 3 or 4 inches. Then get 50 foot of 1/2 inch sisal rope, fasten it with a cable clamp, to the wood, and continue to wind the sisal very tightly around the post coil over coil. You should wear leather gloves as you are pulling very hard on the rope to make tight coils around the wooden post. When you get up past the top carpet piece so that no wood is showing, then cut the rope and clamp it down tightly with one or 2 cable clamps. Now Kitty has something to really sink those claws in, and they much prefer it to the store bought carpeted scratching posts.. It wears a long time but will eventually wear out with daily use. you can save some rope by carpeting the lower part of the post and starting your rope higher up, depending on the size of your cats, it you have little ones, they will use the bottom portion, but a big ole kitty standing on his hind legs and stretching up needs to be able to reach up pretty high. You can see what they are trying to achieve with sinking their claws into something substantial (like the tightly wound sisal rope) as it pulls the outer worn layers of their claws off, exposing new freshly sharp (as a needle!) claw underneath.
James K0UA