If your cats are anything like mine, chances are they have tried to climb the curtains at least once. Constantly replacing your blinds will cost money and you do not want to buy a new pair just for your cat to destroy. There are ways to train them to stop climbing your curtains without actually harming them. If you want to know how to do it, then read on.
I'm going to suggest using a principle known as classical conditioning to associate your cat climbing the curtains with something unpleasant, like a loud bang or other noise.
Classical conditioning is used for many years in all aspects of life, like your bombarded with it every day in advertising. The primary use is to either a human or pet associate a pleasant or unpleasant situation with a behavior you would rather encourage or discourage. So using classical conditioning, we associate actions your cat climbing curtains with an unpleasant noise.
The most effective thing I did train them to stop climbing curtains with a rolled up newspaper. Make sure you have a newspaper handy in the area where they tend to climb, so every time you see it trying to do, you will be able to fear the newspaper on a hard surface to a loud sound network. This should distract them or if they both climb the curtains, you are halfway to their attention and demand in a firm, low voice to get started. If your cat ignores your request to get started, you can press the paper on something hard (especially cats!) So they jumped from the curtains. This is your first step in telling your cat that this behavior is unacceptable.
You must repeat this action every time you try to climb the curtains or manages to climb, otherwise you will send your cat mixed signals and you will not be able to teach your cat to stop this behavior.
When this is successful, you will see your cat without hitting the paper when they are considering as you climb the curtains or midway through the curtains, and they will actually stop and come down. I used to just say, my youngest cat "I get the paper" would jump down.
You might find that you have successfully managed to train you not to climb the curtains but your cat as a child will try to push your limits sometimes and you can find them again to climb the curtains. If this happens just bring it back the next time your cat considers climbing curtains bang on a hard surface as this will quickly remind them that this behavior is not acceptable.