Magic squares
Harimohan Singh Aithani aka Harsh (b Feb 1, 1975) of Kapkote, Uttarakhand has been making handmade magic squares, a hobby since 2009. By June 30, 2014, he had written 25,000 magic squares on nearly 450 chart papers taking 1,260 hr. Finally he bound the papers to make an 18 × 8 inch book weighing 13 kg. He can make a small magic square (3×3) in 10 sec!
http://www.limcabookofrecords.in/recordDetail.aspx?rid=202