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- Title
A NEW COPY PENCIL.
- Authors
Helldorfer, Heinrich
- Abstract
This article focuses on the restoration of pencil erasures and consideration of its chemical properties. A new pencil called Mars-Irremovo Pencil 7001 developed by a Nurnberg pencil factory in Germany, is able to serve most of the hitherto existing problems in making obliterated writing visible. The quality of the pencil, which is so very important for criminal investigator is made possible by the calcium chloride contained in the pencil leads. Writing done with the 7001 pencil can, it is true, be partly removed with a hard rubber eraser, but complete erasing is possible only if the surface of the paper is severely damaged. Removal of writing made with the 7001 pencil by solvents applied to the writing by a wad of cotton wool, was not possible in any case. Lines made by the 7001 pencil, of varying thickness down to very fine, scarcely visible lines, were exposed for four weeks to daylight, without it being possible to detect any bleaching of the same. The lines are not affected by daylight. Investigations concerning the similarity to ink of the writing made with the 7001 pencil showed that this writing left a latent image on the paper which was in contact with this writing for about three weeks.
- Subjects
PENCILS; CALCIUM chloride; ERASERS; PRIVATE investigators; SOLVENTS
- Publication
Journal of Criminal Law, Criminology & Police Science, 1953, Vol 43, Issue 6, p834
- ISSN
0022-0205
- Publication type
Article
- DOI
10.2307/1139775