WINDISCH GRAETZ PRINTS

Found these set of six prints at a charity shop and paid $8,they looked rather regal to me and had to have them,they are depictions of the SPANISH RIDING SCHOOL,these horses were exported to lippzinger in Austria and are the original stock of what is known as the lippzinger horses,the artist WINDISCH GRAETZ is supposedly quiet famous,Thats as far as my knowledge goes regarding art , I am afraid,This is alien territory to me,so any art fundis out there who can contribute ? ,thanks in advance.