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Letter: Letters: Now you see it . . .

Published 30 January 1993

From SHIVA JAGGERNAUTH

Your list of the 10 best inventions from your Feedback summer competition
(19 September) was very interesting. In fact, the idea submitted by Steve
Anastasi about a printer’s ink which, when subjected to a catalyst, breaks
down into a clear substance, thus avoiding expensive de-inking plants when
recycling paper, inspired me to work out a solution to this problem.

The complex of starch (amylase) with iodine, which is blue-black, is
very stable under room conditions and at high temperatures. This can be
used as the inexpensive ink. To remove the ink when recycling, you simply
spray the enzyme a-amylase onto the paper. This will completely remove
the ink in a matter of minutes. The paper is then heated to destroy the
enzyme and so can be reused as new paper.

Shiva Jaggernauth Trinidad, West Indies

Issue no. 1858 published 30 January 1993

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