Indelible Pencils are pencils that are like their Copying counterparts, except for the fact that Indelibles produce a different color mark when the original mark gets wet.
Copying Indelible Pencils are pencils that are both copying and indelible. The branding on the pencil says that it is Copying, while the mark is black, when it gets wet it changes colors. It is an indelible in all ways except in the fact that it changes the color.
The main ingrediant in Indelible Pencils is Metyl. Either Methyl Blue (Noblot Varieties) and Methyl Violet (all others). The main type of Methyl Violet used is Pentamethylpararosaniline hydrochloride, or Methyl Violet 2B (color index no. 42535).
History of Indelible PencilsEdit
The First IndeliblesEdit
Prior to the introduction of the copying varieties, the term Indelible referred to pencils with silver nitrate-based formulations introduced in the late 1850's.
Early copying pencil patents however, indicated that they were also initially concieved for Indelible Pencils, which this has ultimately dominated.
One 1877 patent for a copying pencil describes its usefulness as an "ordinary lead pencil...but more permanent, as the marks cannot be erased with rubber".
List of Indelible Pencils, Assorted by CompanyEdit
- Eberhard Faber Blu-Blak
- Eberhard Faber Noblot
- Eberhard Faber Mongol Copying
- Sanford Noblot
- Faber Castell Noblot
18.104.22.168 18:06, July 2, 2012 (UTC)
- Dixon Eldorado Indelible Copying
- Dixon Intenso Intense
- Venus Copying
- Mephisto Copying
- Eagle Manifold
- J.S. Staedtler "Approved"
- J.S. Staedtler The "Moon"
- American Copying
- General Copying