M Ramya Muthu  (Jul 14, 1999)  from Ramanathapuram, Tamilnadu, have made a record by making  biggest letter cover of 12  feet length  and 5 feet width on Feb 13, 2017 at Ramanathapuram.

http://indianachieverbookofrecords.com/m-ramya-muthu-made-biggest-letter-cover/