cool. sorry one more question - haven't seen these around, what shops sell them?
No worries, pai. Make them yourself. All you need to do is to get a frame to secure them on. You should be able to buy the screens from a hardware store or Home-Fix.
It's really easy. Just be sure that you remove the access water with a clean and grit-free squeegee, and that your drying area is free from dust. Ensure that there's a good airflow between screens if you decide to build multiple screens.