Cat claws. dria, please do not declaw your cat. This means that you place furniture as a higher priority than the annoying little bastard. Please either a) give the cat to someone with different priorities, or b) don't buy furniture that concerns you so.
Besides, scratchability is really a function of surface texture, and the ability for them to sink their claws into the material. Step 1: Get a sacrificial anode, such as a scratching post or one of those ball-in-track deals with the coiled cardboard centerpiece. Step 2: Don't buy tasty claw furniture. For instance, I have a very nice Italian leather couch. The cats don't touch it, because the leather surface is not appealing to them for scratching.
As an optional Step 3: Have you ever noticed how quickly cats run from compressed air, such as from one of those bottles you dust your keyboard with? Whoo! Negative feedback generally doesn't work with cats (they just learn not to behave that way in your presence), but it sure can be fun to watch them scramble from time to time.
And please don't use neutering/spaying as a counter example of owning cats under our own terms. Scratching furniture does not produce more cats.