Facsimile (Latin: fac simile?to make similar) is the term generally used to describe the most natural possible reproduction of an original (image, handwriting, book) complete with all its characteristics including dirty marks, damage or traces of use. This is the highest degree of similarity which a reproduction can achieve in comparison to the original, and nothing is added, left out or improved. Copyists in the Middle Ages were already trying to achieve reproductions of texts and books which were true to the originals by writing them out and illustrating them by hand. The first full facsimiles date from the early 17th century, and were engraved in copper. Facsimiles were also produced using the wood engraving method. The invention of lithography in the late 18th Century and collotype in the mid 19th Century made facsimiles as we understand them today possible. Collotype is still an ideal method of reproducing color originals, but it is very expensive.