Cat scratching rope is made out of 3-strand sisal rope. Normally the posts are made out of 6mm, rope depending on the size of your cat scratching posts/trees. Obviously the bigger the posts the larger the diameter needed. Sisal rope is made from a hard natural fibre. It has excellent resistance to sunlight, little stretch and good knot-holding abilitySisal Fabric vs. Carpet for Cat Scratching Posts
When you visit stores and look at catalogs, you will see many scratching posts that are covered in carpet, but there are several negatives to using that material, including:

Carpet doesn’t shred when a cat scratches at it. Instead, it usually catches the cat’s claws and pulls on her toes. This is upsetting to her and often results in avoidance of the post. Many people who believe their cat won’t use a scratching post have only provided carpet-covered varieties. Their cat has taken one swipe, found it to be objectionable, and never touched it again.

Carpet may be found elsewhere in your home. When you are trying to teach your cat to scratch a post and not household items, it’s best to provide a post covered in a material that isn’t found in other spots in your home. Your cat should be able to clearly tell the difference between the items she is allowed to scratch and those she is not. Therefore, carpet is not a good choice for many households. Sisal is an excellent material for providing the necessary distinction between scratch-appropriate and scratch-inappropriate items.

What is Sisal?

The best rope to be used on cat scratchers is made from sisal. It’s an extremely stiff fiber that comes from the agave plant, aka the American aloe. At first glance you might not consider that little cactus to be all that robust, but sisal rope is surprisingly durable and long-lasting, and can withstand many years of your cat’s attempts at shredding, making it the optimal choice for a scratching post that can stand up to your destructive kitty.

Why Cats Love It

Sisal is tops as far as durability goes when it comes to scratching posts, but another benefit is that cats are drawn to it. It’s texture is rough, like tree bark, so it naturally cries out to your cat to be scratched at, mercifully calling her attention away from your sofa.

Rope or Fabric

You’re probably most familiar with sisal rope cat scratchers, but sisal is available in a fabric, too. It has a rough texture, like the rope does, so your cat will be inclined naturally to want to sharpen her claws on it. However, being fabric, it isn’t quite as durable as the rope. The advantage of being less durable is that your cat will be able to shred the fabric with enough work, so she’ll feel a sense of accomplishment. However, that also means you’ll have to replace the fabric more frequently than you would the rope.