Some cats might scratch their way through screens, whereas others might be able to actually push through the screen with their body weight, so you have to either proof your window for both or keep in mind what your cat is capable of.
Scratch Damage vs. Cat Safety Note that sometimes screens advertised as pet safe just guard against scratching damage rather than effectively keeping a cat from getting out a window.
Designated Outdoor Area: You may also want to consider designing an outdoor area for your Ragdoll kitties. For example, letting them out occasionally so they will be less tempted by the call of the outdoors.