1, glue stick: you can apply a small amount of glue stick on the back of the window grilles, so that it can stick firmly and take it off next year.
2. Toothpaste: It is also a good method to apply less toothpaste to several parts of window grilles.
3, soapy water: You can apply a small amount of soapy water to the curtains, but this method will not stick for a long time.
The above is the method that I share with you to paste flannel window grilles on the glass. I hope it will help you.