kosmoskynä

Tyydyn URLahtelemaan:
http://www.brandnamepencils.com/brands/vera/kosmos1610m.shtml
http://www.wisegeek.com/what-is-an-indelible-pencil.htm

Netti tietää:
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Copying pencils were invented in the 1870’s and within a decade had overtaken the wet ink press method of letterpress copying. The younger generation might not know the magic of the colourful purple pencils. They were the predecessor to the ball point pen. Similar in appearance to graphite pencils, copying pencils contained a dye which turned purple when moistened. They were marketed as a product which could not be erased because the main component of the pencil was an aniline dye which produced a purple colour when dissolved in water or alcohol. The other components of the copying pencil were clay (kaoline) and graphite. Other colours used were red, black, green and combinations of dyes. The aniline dye in the copy pencil produced stronger copies and more copies. Another advantage was that the aniline dye was not affected by exposure to the air (as was the ink) and therefore copies did not have to be produced instantly.

http://www.awm.gov.au/blog/2007/04/17/the-magic-of-purple-pencil/
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Samalta saitilta löytyy lisätietoakin kopiokynästä. Tämän kirjoittaja osti kahdeksankymmentäluvulla pienen kirjakaupan koko kosmoskynävaraston muistoesineiksi. Lisäksi hän laati veroilmoituksensa aina kosmoskynällä, niin kauan kuin veroilmoitus vielä piti jättää kirjallisena – nykyään se hoidellaan verkossa.