If you mean isinglass you may try:

L.Cornelissen & Son
22 Great Queen St.
London WC2 5BH
United Kingdom

James Vickers Ltd
The Isinglass Factory
West Street
Coggeshall, Colchester
Essex
United Kingdom

Kremer Pigments
61 East 3rd St.
New York, N.Y.10003

However, my definition of isinglass comes from SSCR Journal, Nov 1994:

"The word isinglass is derived from the obsolete Dutch word huisenblas
which literally means 'sturgeon's bladder' [...] Isinglass has been
used since the seventeenth century in the conservation and restoration
of flaking paint on icons.  It is also used as an artist's binding
medium.  In conservation, isinglass is used currently for the
consolidation of paint in easel painting, panel painting and icon
conservation."

I hope that helps.

Juan (with the assistance of Beata)

Kari Laurent wrote:
>
> Does anyone have a source for eisenglass?  I'm told it's a type of plastic
> used in the "windows" of old cast iron woodstoves.
>
> Kari Laurent, Collections Manager
> Cave Creek Museum, Cave Creek, AZ