To clean and shine your window panes, Valmour proposes  Meudon Whiting LOUIS XIII , a very fine-grained natural chalk which allows to clean and add  shine to glass surfaces.  

. Dilute 1 volume of Meudon Whiting LOUIS XIII in 3 volumes of water.  
. Spread on the glass.  
. Let dry.  
. Wipe with a Cotton Cloth for DIY.