FIXING, WASHING, AND DRYING 409 



chemical should be carried out in open space or a well-ventilated room. Fumes of 

 ether should not be breathed as it is an anesthetic. 



Plates and films are usually dried vertically by placing them in racks or hanging 

 them by clips from some convenient support. In this case evaporation may take 

 place from both sides of the material. On the other hand, prints are often dried bj^ 

 placing them on a horizontal surface or by squeegeeing them to ferrotype plates, in 

 which case effective evaporation can take place only from one surface of the print. 

 Another common method of drying prints is to place them between white lintless 

 blotters or alternate layers of blotting paper and waxed sheets. Pressure may be 

 applied to a pile of such prints to reduce the tendency of curling. 



Water spots on negatives result from the accumulation of water particles into 

 drops. In drying, the gelatin swells at the edge of the drop and forms a crater around 

 the perimeter of the drop, which remains after the drop has completely evaporated. 

 The additional thickness of gelatin at the edge of the crater shows up later in the 

 print as a slightlj' dark ring or stain. It is sometimes possible to remove such water 

 spots by soaking the negative again in water and drying as uniformly as possible. 

 Removal of the excess surface water will assist in minimizing stains due to water 

 drops. Another method of removing drying marks is to completely bleach the film in 

 a solution of 



Potassium bromide 10 gr. 



Potassium feriicyanide 10 gr. 



Water 1 oz. 



After bleaching, the negative is washed and then fully developed in a nonstaining 

 developer. 



Drying of Prints. — After a print has been washed thoroughly, the surface moisture 

 may be removed by swabbing with a piece of wet absorbent cotton and the print 

 placed in a rack, in a print dryer, or on a flat surface to dry. If the hardener in the 

 fixing bath has hardened the emulsion side sufficiently, the print may be blotted 

 by means of a moistened viscose sponge, or the excess water maj^ be removed by a 

 squeegee or print roller. The print is placed emulsion side against a clean flat surface, 

 such as the polished surface of a ferrotype plate, and the surplus water is removed by 

 running a rubber straightedged squeegee or a print roller over the back of the print. 

 The print may be left on the ferrotype plate, if one is used, until it is thoroughly dry, 

 when it will peel off easily. 



The print may also be placed upon a drying stretcher, which consists of a frame 

 of wooden strips, across which have been stretched sheets of thin porous cloth such 

 as cheesecloth. Such a frame may be used in the open, or it may be placed in a 

 warmed drying oven. In either case it is desirable to turn the prints over occasion- 

 ally so that the tendency toward curling may be reduced. 



The time required for a print to dry will depend upon the degree to which the 

 emulsion has been hardened in the fixing bath, the extent to which the surplus water 

 has been removed from the print, the temperature and humidity of the drjdng atmos- 

 phere, and the weight or thickness of the print paper. 



Curling of Prints. — Prints frequently have a tendency toward curling. This is 

 especially true in the case of prints dried on a drying stretcher and in the case of prints 

 having a glossj" rather than a dull or matte surface. If a slightly excessive amount of 

 hardener was used in the fixing bath, and if, moreover, the temperature was above the 

 ordinarj^ room temperature and the humidity low, the crispness will be present to the 

 extent of brittleness, with an inclination to crack, making it easy to injure the print in 

 ordinary handling. Such an objectional condition in which a print dries when this 



