COATING THE PAPER
Some papers have one side that is smoother than the other. If this is the case the smoother side is the one to print on. Tape the four corners of the paper to the tabletop with drafting tape to keep it from moving around while you spread the sensitizer, which is applied at a rate of 1 milliliter for every 40 square inches of image area. The sensitizer is made by mixing equal parts of the platinum/palladium solution and ferric oxalate solution together just prior to coating. For example, to coat a 4 x 5 test print which is 20 square inches, add 1/4 milliliter of platinum solution to 1/4 milliliter of ferric oxalate solution for a total of 1/2 milliliter in the shot glass. Swirl it around to mix it; now it is ready to pour onto the paper. The peroxide solution (3% hydrogen peroxide) if needed to boost contrast is added to the sensitizer immediately before pouring it onto the paper. The contrast increase varies from paper to paper, but .05ml per ml of sensitizer gives considerable contrast increase and is a good place to start experimenting. To avoid diluting the sensitizer excessively, do not exceed 10% of the total volume of sensitizer with the peroxide.

Many printers (and clients) like to show evidence of the hand coating by showing brush strokes around the edges of the print. This is easily accomplished by coating an area slightly larger than the negative and the brush strokes around the print area will show up when processed. Brush marks around the edges will also hide any slight fogging or staining on the print. If clean edges are desired, cut a mask with rubylith and tape the negative to it before printing.

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 d6ne each time you coat and will keep the brush from absorbing and retaining too much sensitizer and insure consis- tency 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 touch- ing the paper, quickly spread the sen- sitizer 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.