Why did the new-technology i.e. mechanical printing as developed by Johann Gutenberg not displace not displace the art of producing books by hand? what were the effects of new technology?

(a) The new technology did not entirely displace the existing art of producing books by hand due to following reasons:
(l) The printed books at first closely resembled the written manuscripts in appearance and layout because the metal letters imitated the ornamental hand-written styles.
(ii) Borders were illuminated by hand with foliage and other patterns.
(iii) Illustrations were painted.
(iv) In the books printed for the rich, space for decoration was kept blank on the printed page, so that the purchaser could get it designed as he desired.
(b) But in spite of the above facts, the new technology became popular because between 1450 and 1550, printing presses were set up in most of the countries of Europe. The number of printed books increased from 20 million copies in the second half of the 15th century to 200 million copies in the 16th century. Thus shift from hand printing to mechanical printing brought a print revolution.