From: TERRY KING, INTERNET:101522.2625@compuserve.com
TO: Multiple recipients of list, INTERNET:ALT-PHOTO-PROCESS@VAST.UNSW.EDU.AU
DATE: 08/03/96 10:57
Richard, Judy Keith Kerik
In response to further enquiries I forward to the list a slightly amended note t.
that I sent to Keith in March.
SIZE FOR PLATINUM AND OTHER SENSITISING SOLUTIONS
"Terry,
Would you be kind enough to email me a description of your sizing
procedure. I thought you had done this on-list already but I can't
find it. Please be as specific as you can.
Much thanks,
Keith"
Keith
I may be teaching my grandmother to suck eggs with you but I will go into detail
in case any neophytes are listening.
Recipe for the sizing of paper for platinum/palladium printing, to make 100 ml.
Ingredients
260 Bloom deionised ossein ( hard gelatine) 1 g
Purified or distilled water 100 ml . Tap water must not come into contact with
the ossein, the paper or the brush during the operation.
Utensils
A 250 ml glass beaker
A larger glass beaker
A china plate
A bound hake brush kept for this purpose and none other. Write " GELATINE SIZING
BRUSH " in water-proof ink on the handle.
Time
Less than an hour.
Method
1. Take the 1 g of ossein and and 5 ml of the 100 ml of purified water and
place in a small Pyrex beaker ( I use glass 200 ml urine specimen jars) and
leave for thirty minutes or until the ossein has soaked up the water.
2. Heat the remaining purified water to 38C and add to the swollen ossein and
stir with an inert stirrer for example a glass rod..
3. Place the beaker containing the ossein in a water bath i.e. a larger
container, a bigger jar, with water at 45 to 60C and keep the water at that
temperature.
4. Stir the ossein from time to time until the ossein has completely dissolved.
Hold the small beaker against the light until you can see that all transparent
filaments of ossein have dissolved and the 'solution' is completely clear.
The size is now ready for use.
5. Wash the bristles of the hake brush in purified water and remove excess water
until the bristles are damp.
6. Warm the plate and dry it.
7.Pour sufficient warm ossein onto the warm plate.
8. Load the hake brush from the warm plate and spread the warm ossein onto the
paper as quickly as you can; hold the paper to the light to ensure that there
are no dry patches left. The ossein must not be allowed to gel at this stage
9. Place the paper in front of a fan heater immediately so that the temperature
of the ossein does not fall below 35 C.
10. Dry until there are no damp patches showing.
11. Humidify the paper over a tray of warm water in a cupboard before applying the sensitiser.
The paper is now ready for coating.
Note: the ossein is cheap so only make up enough for the day. Do not use
poisonous preservatives. It should last one or two days and can be allowed to
gel and be heated for further use but only two or three times. Do not heat beyond 65 C as
the material will lose its gelatine characteristics.
Terry