''It took me 12 hours from eight pm in the evening to complete the piece measuring 20.30 metres in length and 1.4 metres in width,'' Apuraj Barooah told PTI.
An award from the Guinness authorities along with a certificate was presented to Barooah for his effort in London on July nine.
Jack Brockman of the Guinness World Records, said, ''We are happy Barooah has achieved the record for the longest scratch art piece. His piece contains 40 pictures of world folk dances including the famous Bihu dance of Assam.''
Brockman said, ''All the criteria were examined in the presence of some 45 people and we are proud of him.''
Scratch art or scratchboard art is a technique where drawings are created using sharp knives and tools for etching into a thin layer of white China clay which is coated with black ink.
Sometimes other coloured layers are used to add variation in colour to the piece, but Barooah has developed the interesting new process which he named "Bromide Scratch Art".
This involves scratching bromide paper with a razor blade to reveal reds, oranges, yellows and whites beneath the exposed black face of the paper, he says.
Barooah said in London he was presented with a ceremonial hand-woven scarf to be worn around neck. The piece depicted a landscape with fold dancers from 40 countries including India, UK, USA, Spain, Italy, China, Australia, Brazil, Japan, South Africa, France and Thailand.