Celluloid Staining from Ink or Latex Sac

[VacNut]

This is a continuation of a topic that started with celluloid rot.

 

Vintage celluloid pens often are discolored to an amber or brown color. Vacumatic barrels often show the ambering in the transparent laminations of the barrel. (I have noticed that Golden Web Vacs typically are only ambered at the barrel. The celluloid is unstained at the cap).

 

Jade Duofolds have discolored barrels and at the middle section of the caps. 

It is very common to find Duofold Deluxe Pens ambered the full length of the barrel with relatively clean caps.

 

One theory is that the ambering is the result of sulfur outgassing from the latex sacs or diaphragms.

 

Another theory is that the pigments or chemical composition of the ink is absorbed by the clear or light-colored celluloid.
 

In either scenario the celluloid acts as a wick that absorbs the discoloration throughout.

 

I am currently working on a Soennecken 111 which has a transparent end where the barrel meets the section to view ink capacity. The transparent end is ambered. The filler end of the barrel is crystal clear as though it just left the factory. 111s use a piston filler with a cork seal. The cork remnants were inside the barrel when I cleaned the pen.

I am not aware of any latex in the pen (perhaps the ebonite feed?).

For me this is a case of ink discoloring the transparent section.

 

I am curious on people’s experiences or if anyone has theories on what causes the discoloration.

 

Perhaps both methods cause the discoloration?

 

 

 

 

[FarmBoy]

Discoloring caused by ink is called a stain. 
 

 

[VacNut]

Not a stain if it can’t be removed. Could the pigment be absorbed by the celluloid?