A quatrain written diagonally is nastaliq Calligraphy [slides]  British Library 

 - London  British Library 
 - 1 Slide  Col.  ill  35mm. 
 - Indian Miniatures Collection from British Library .
<br/><br/> IGNCA slides collection, cross reference Indian Miniatures in the India Office Library,p.7p 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Painting-India-1633-42 A.D.<br/>Mogul painting<br/>Calligraphy, Mogul
<br/><br/><label>Dewey Class. No.: </label>BL-IM  / 68 (48v) Add or 3129 K-82592