Film: Kodalith Ortho (available in 100' bulk rolls). Because it is an orthochromatic film it can be handled under the red 1A safelight. Kodalith Ortho sees blue as though it were white and red as though it were black. Because it is an extremely high contrast film it should only be used with high contrast art work where it will hide most cutout edges or whiteout. Art work with grey tones should be avoided because it will reproduce rather unpredictably when photographed with Kodalith. Darker tones will become transparent and lighter tones black with some mottling in between.

Exposure: 1/4 second @ f10 (with the two orange 650 watt lamps). Kodalith is a very slow film with an ISO speed rating of 6.

Processing:  

The developer must be made just prior to use by mixing together equal parts of Kodalith A and B. You will need 200 ml. at 20^o C. for each roll of 35mm film. Be very careful about the temperature. Since the developing time is so short, pour the developer into the tank, load the developing reel under the safelight and drop it into the developer. Then put on the tank lid, turn on the room lights and agitate continuously by inverting for the whole development time.

For slides that are to have white lines on an opaque black background (and are suitable for hand colouring with food colouring) skip the steps indicated with a star (*). The film then goes directly from the fixer into the final wash. For white on blue the extra steps are necessary and the film should be regularly agitated every 30 seconds through them. Both the toner and the bleach are unstable and must be made up just prior to use. All the chemistry is discarded after use except the fixer which is returned to its jar.