POSTCARDS The popularity of the postcard (invented in 1869 by Dr. E. Hermann, of Vienna) has increased enormously since about 1894, owing to the intro duction of picture postcards, the authorising of private postcards, and the withdrawal of the regulation confining the written matter to one side only. As to who first produced a picture postcard there appears to be some difference of opinion; it is known that at the time of the Franco-German war a French stationer published such a card to commemorate the visit of a popular regiment to his city.
Postcards ready sensitised are supplied by the dealers, or any good cards may be sensitised at home by the blue-print, kallitype, silver or other processes. Plain postcards are sometimes not pure enough to produce the best effects, and it is always better to purchase them ready sensitised with bromide or print-out emulsion, or to obtain the unsensitised cards from a manu facturer of sensitised postcards.
As negatives may be larger or smaller than the average postcard (5i- in. x 31 in.) care is necessary in printing and masking. Many special kinds of postcard printing frames are obtainable, but an ordinary large printing frame can be made to serve. Half-plate is a handy size from which to print a postcard, as the image can then extend right to the edges. Smaller plates than postcard size need masking, which may be done by using a half-plate frame and placing in it a piece of plain glass and a piece of white or light cardboard. In the cardboard is cut an aperture large enough to take the plate. Lantern binding strips are then placed over the junction of the card and the negative (see A), to hold it in position and to serve as a mask for giving a straight edge to the picture. When
the correct position of the image on the postcard has been found guide marks c are made on the cardboard to enable cards to be placed in posi tion quickly (see diagram A). Packets of post cards very often contain black paper masks with openings of various shapes, and these are extremely useful. For the addition of borders, see " Border Printing " and " Borders, Fancy," and for the addition of titles, see " Lettering Negatives and Prints." Postcards are exposed, developed, toned, etc., in the same way as other prints, but there is sometimes difficulty in causing them to dry flat. Collodion and most self toning cards may be dried under pressure between blotting-paper, but gelatine-surfaced cards would be spoilt by such treatment, al though the risk would be reduced by hardening with formalise. One of the best ways of drying gelatine cards is to bend them archways, picture side outwards, and catch the ends in corrugated paper as at B. Large producers sometimes nail laths to a board and use the board in the same way as the corrugated paper. The cards generally flatten out naturally when released, or may easily be made to do so, whereas if allowed to dry naturally, they curl inwards and often crack, especially in the case of collodion cards, when any attempt is made to flatten them after drying.