EXPOSING THE PAPER
In all probability, you will be making a test strip on a coated piece that is small- er than your final image size. I coat a 4 x 5 area to test for an 8 x 10 image, and 5 x 7 for larger prints. Place the test under the part of your negative that contains the highlights. Just like in any other form of printing the exposure controls the highlight values and the level of contrast controls the shadow values. The time for each "strip" will vary with the light source, negative density, and amount of contrast agent in the sensitizer, but will not be under 3 minutes under the most favorable conditions: Bright sunlight or unshielded blacklight tubes, properly exposed and processed negative and sensitizer without peroxide. Adding peroxide will increase the exposure by one half to one full stop depending on the amount.

After exposing the test strip, open up half the print frame under dark- room illumination and examine the coated paper-you should see a faint provisional image caused by the reduction of the ferric oxalate to ferrous oxalate. The intensity of this image is dependent on the relative humidity of the paper and composition of metals in the sensitizer and cannot be used as a judge for the proper exposure, but will tell you if you are close. If there is no image, close the frame and increase the exposure until you can see that faint image when you open the frame. The paper is now ready for processing.

The foam brush used for spreading the sensitizer is prepared by wetting the very tip of it with distilled water and shaking the excess out. This is done each time you coat and will keep the brush from absorbing and retaining too much sensitizer and insure consistency from coating to coating. What you want here is a thin damp edge on the brush. Pour the sensitizer inside your coating boundary and, holding the brush vertically and barely touching the paper, quickly spread the sensitizer around evenly until it starts to soak into the paper. Excess brushing will abrade the surface of the paper showing streaks and mottling. Coating is an acquired skill and it is a good idea to practice with water that has a little food coloring added to it until you feel confident enough to go to the sensitizer. After coating, place the paper into your drying box and turn on the hair dryer. Then, rinse the edge of your brush with distilled water and shake it out. When the thermometer reads 1 IOOF, it is ready to expose.

PROCESSING THE PRINT
The developer recommended in the previous article works best in a temperature range of 60 degrees F, to 75 degrees F. Place the print face up in a clean tray, and while holding the tray at a slight angle, flow the developer quickly and evenly over the print and continue to agitate for one minute at which point development is complete. Unlike silver printing this is a completion reaction and developing longer will not darken the print. I leave the print in for a total of five minutes with agitation because the extra time (with this developer) helps clear the print as it starts to dissolve the iron compounds that will be fully removed in the clearing baths. Pour the developer back into its container (if you have any cuts or nicks on your hands wear gloves here - oxalate compounds are poisonous) and without rinsing pour in the first clearing bath (0.3% HC1) and agitate for 1 to 2 minutes. 8 x 10 inch prints need about 500 milliliters in each clearing bath. The first bath will take on a yellowish-brown appearance from dissolved iron and platinum/palladium compounds and should be discarded after use. Pour in the second clearing bath, agitate for 1 minute, pour it out, and save it. This will become the first clearing bath for the next print. It should be just faintly yellow indicating that the first bath removed almost all the metal salts from the print. Pour in the third clearing bath and agitate for 1 minute, after which it should remain perfectly clear indicating that all the metal salts were removed by the first two baths. Save this third bath as it will become the second bath for your next print and you will only have to make a new third bath. Unless you want to keep the test for a long time, you only need to rinse it briefly in running water and dry it for evaluation.