PACKING PLATES The question of packing—or, rather, re-packing —plates after exposure is of importance to the tourist. He should remember not to throw away the outer wrapper and the inner packings, as these will come in useful. The best way to remove the outer wrapper from a box is to cut across the centre all round with knife or pocket scissors, so that each half may then be slid off, as shown. When required, the two halves may be replaced and bound together with strips of gummed paper, thus making it practically impossible to open the box accidentally. Ex posed plates should be placed film to film, and the pairs—usually six—wrapped in a solid block in brown or other opaque paper and pressed into the original box, using paper pads at the ends and sides of the box to prevent the plates rubbing together and shaking about loose in the box ; the lid is then replaced, then the outer wrapper, and the whole tied with string or bound with gummed paper. It is a common practice to put pieces of paper between the film sides of the plates, but newspaper or other printed matter must not be used, because the printer's ink has an action upon the sensitive film and becomes transferred to the picture, invariably showing badly when the plate is developed. If the printer's ink is seen upon the
plates before development, it may sometimes be removed—in the dark-room, of course—by rubbing with benzene upon cotton-wool. Even when white paper is used between the plates there is a risk of fogged patches appearing, and cigarette papers have been known to fog plates very badly. It has been suggested that white paper possesses luminiferous or phosphorescent properties—extremely faint, of course, but suf ficient, over a period of several weeks, to cause fogging. In spite of this, however, white paper is commonly employed.
Other errors in packing are due to ignorance of the fact that pressure will exert an influence upon the sensitive emulsion. An envelope con taining an exposed plate is often written upon, and if the writing is done upon the side rest ing upon the film a reproduction will more often than not be found upon the negative. Should it be necessary to mark exposed dry plates, the writing should be done in very small characters on one of the extreme corners of the film side.