Re: "ox-gall"

Juan,

It is an organic product from the gall bladder of an ox (cattle): in other
words, bile. I used to make marbled papers (like those found inside the
covers of old books) and ox gall was added to the water colour pigment to
help it flow out evenly when it was floated on a layer of mucilage obtained
from boiling irish seaweed (carragheen moss).

I think that it is still much used today - watercolourists use it for its
surfactant qualities (i.e.: it is used as a wetting agent, reducing surface
tension, it is good for laying down an even wash of pale watercolour), but
the type they use differs slightly from that used in marbling paper.

When fresh ox gall is light and almost odourless, but as it ages it becomes
increasingly darker and foetid - it does not keep well. I think that there
are other synthetic agents in use today that can be substituted for ox gall
in watercolour painting - like photoflo - but these are not so successful
for marbling. Ox gall has a fatty content - it can mix with water or
oil-based materials. In marbling, the fatty content helps to stop different
watercolours from mixing together once they are dropped onto carragheen
liquid and combed out into patterns.

Regards,
Neil.

> Translating an old text has more than enough coal printing, the word
appears
> "OX-GALL" that translates you as "BILE OF OX."
>
> Can somebody explain the meaning of "ox-gall"?.
> What product can it be similar at the present time?.
>
> Thank you.
>
> Pardon for my English: text translated by computer
>
>
>
Received on Thu Apr 15 07:46:15 2004