Pipets
A more precise method of measuring the expensive sensitizer solution than the traditional "drop" method is needed, as the size of the drop varies with the size of the bore of the dropper, the viscosity of the solution, the atmospheric pressure, etc. Measuring pipets, available from chemical supply houses, are the answer to this problem. For small prints up to 8 x 10, two 1 milliliter pipets (one for the platinum solution and one for the ferric oxalate) graduated in tenths of a milliliter will be just right. For larger prints use two 10 milliliter pipets graduated in tenths. The hydrogen peroxide solution is used in much smaller quantities, often less than one drop for small prints (there are approximately 20 drops per milliliter) so a micropipet of 1/10 milliliter graduated in hundredths is called for. Practice pipetting with water first until you are skilled enough not to draw up too much solution and get it in your mouth, or use a piped bulb to get the solutions up into the pipet.

Wash Bottle
For dispensing distilled water to pre-wet brushes, rinsing the shot glass, rinsing the brush after coating, and cleaning the pipets between coatings. 16 ounce polyethylene "squeeze" wash bottles from chemical supply houses are perfect for this application.

Drafting Tape
Removable drafting tape is used to hold down the paper for coating and to desig- nate the coating area when an image size smaller than the paper used is desired. For consistent results it is important to use the same volume of sensitizer for a given coating area (one milliliter per 20 square inches) and setting the boundaries with tape is one way to be sure this happens.

Drying Box
The freshly coated paper needs to be dried quickly and evenly to prevent the sensitizer from sinking in too deeply. Hanging the paper and blasting it with a hair dryer in the darkroom is inconsistent and dangerous as dried, poisonous oxalate compounds are blown into the air. A very simple drying cabinet can be made from a large cardboard box like the kind paper towels come in at the supermarket. Straighten out a wire coathanger and run it through the two small holes on opposite sides of the box about two inches from the top so you have something to hang the paper from using plastic clothes pins. About two inches from the bottom of the box cut a hole just large enough so that it is a snug fit for the nose of the hair dryer you will use as your heat source. Lastly push the stem of a dial thermometer through the cardboard box up near the top so you can monitor the temperature inside. To use, open the top of the box, hang the coated paper, close the top, turn on the hair dryer, and wait until the thermometer reads 100 degrees F. The paper is now ready to expose, and its relative humidity (which affects contrast, printing speed, and color) should be consistent from print to print. A more permanent cabinet is easily constructed from thin plywood or masonite using a hinged top.

Print Frame
For the production of smaller prints, II x 14 or less, a good print frame is essential. It should hold the negative and paper in firm contact, be made of hardwood and have a locking system that doesn't cause shreds of wood to flake off by using it. The finest printing frames I have ever used are made in New Mexico by Kurt Mottweiller. He is primarily a camera maker, producing exquisite wooden pinhole and panoramic cameras.

For larger prints, I use two sheets of 24 x 32 1/8 inch plate glass with a layer of black felt in between. In humid climates it is sometimes necessary to include a vapor barrier between the paper and the felt, as the felt tends to absorb moisture and can affect the paper's relative humidity during printing. A sheet of black plastic between the paper and felt will prevent this.