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Ink

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Spud McLaren
719550.  Mon Jun 14, 2010 2:06 pm Reply with quote

The Wiki comments on iron gall ink were especially interesting to me:

[from the general Ink page on Wiki]:

Iron gall inks became prominent in the early 1100s; they were used for centuries and were widely thought to be the best type of ink. However, iron gall ink is corrosive and damages the paper it is on (Waters 1940). Items containing this ink can become brittle and the writing fades to brown. The original scores of Johann Sebastian Bach are threatened by the destructive properties of iron gall ink. The majority of his works are held by the German State Library, and about 25% of those are in advanced stages of decay (American Libraries 2000). The rate at which the writing fades is based on several factors, such as "the proportions of the ink ingredients, the amount deposited on the paper, and the composition of the paper" (Barrow 1972:16). The corrosion is caused by "two major degradation processes: acid catalysed hydrolysis and iron(II)-catalysed oxidation of cellulose" (Rouchon-Quillet 2004:389).

Treatment is a controversial subject. There is no treatment that will undo the damage already caused by the acidic ink. Deterioration can only be stopped or slowed for a period of time. There are some people who think it best not to treat the item at all for fear of the consequences. Others believe that non-aqueous procedures are the best solution. And then, there are some that believe an aqueous procedure may provide the answer for preserving items written with iron gall ink. Aqueous treatments include distilled water at different temperatures, calcium hydroxide, calcium bicarbonate, magnesium carbonate, magnesium bicarbonate, and calcium phytate. There are many possible side effects from these treatments. There can be mechanical damage, which would further weaken the paper. The color of the paper or ink may change and ink may bleed. Other consequences that might arise from aqueous treatment are a change of ink texture or the formation of on the surface of the ink (Reibland & de Groot 1999).

Iron gall inks are generally stored in a stable environment, because fluctuating relative humidity increases the rate at which formic acid, acetic acid and furan derivatives form in the material on which the ink was used. Sulfuric acid acts as a catalyst to cellulose hydrolysis, and iron (II) sulfate acts as a catalyst to cellulose oxidation. These chemical reactions physically weaken the paper, causing brittleness.

 
austinallegro
719629.  Mon Jun 14, 2010 5:58 pm Reply with quote

I heard somewhere, that along with lemon juice, urine makes a good invisible ink.

 
Spud McLaren
719642.  Mon Jun 14, 2010 6:39 pm Reply with quote

In that nobody wants to heat it up in order to be able to read it?

 
dr bartolo
735028.  Fri Aug 20, 2010 11:30 am Reply with quote

talking about ink, isn't there a type of mushroom calles theCoprinus comatus or shaggy ink cap, that when left to rot, turns into an ink-like stuff that was actually was used as ink by middle age scribes?

 
tetsabb
735110.  Fri Aug 20, 2010 5:05 pm Reply with quote

austinallegro wrote:
I heard somewhere, that along with lemon juice, urine makes a good invisible ink.


I seem to remember an episode of a certain TV programme in which it was mentioned that a certain other emission (exclusive to chaps) could be used as invisible ink.
How you make it visible again I do not remember.

 
suze
735117.  Fri Aug 20, 2010 5:24 pm Reply with quote

I think that the two usual methods for rendering invisible ink visible both work in this instance - either you apply heat (ironing the message was the method advocated in the secret codes book I had 35 or so years ago!), or you view it under ultraviolet light.

 
Jenny
735119.  Fri Aug 20, 2010 5:29 pm Reply with quote

It has the added benefit of being testable for DNA to prove that the correct person wrote it.

 
bemahan
735122.  Fri Aug 20, 2010 5:34 pm Reply with quote

suze wrote:
I think that the two usual methods for rendering invisible ink visible both work in this instance - either you apply heat (ironing the message was the method advocated in the secret codes book I had 35 or so years ago!), or you view it under ultraviolet light.


So if you iron a chap's pyjama bottoms, all sorts of secret messages might appear?

 
hassan el kebir
735129.  Fri Aug 20, 2010 6:14 pm Reply with quote

bemahan wrote:
suze wrote:
I think that the two usual methods for rendering invisible ink visible both work in this instance - either you apply heat (ironing the message was the method advocated in the secret codes book I had 35 or so years ago!), or you view it under ultraviolet light.


So if you iron a chap's pyjama bottoms, all sorts of secret messages might appear?



What if he's pisslexic? Or you might find he's writing his hidden message in a strange sort of morse code

 
Posital
735170.  Sat Aug 21, 2010 2:06 am Reply with quote

Jenny wrote:
It has the added benefit of being testable for DNA to prove that the correct person wrote it.
And it renders digital signing obsolete...

 
Spud McLaren
735193.  Sat Aug 21, 2010 4:41 am Reply with quote

hassan el kebir wrote:
Or you might find he's writing his hidden message in a strange sort of morse code
Braille.

 
dr bartolo
736202.  Tue Aug 24, 2010 11:32 am Reply with quote

I also heard that sweat could be used to a similar effect, as with spittle

 

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