All preliminary work in cloud printing should be on silver printing-out paper. Working by daylight in a process that gives a very strong image enables the work to be followed easily. The mask can be adjusted to the correct position without any difficulty, and any error in adjust ment or in arranging the card shield can be seen at almost the beginning of printing, and rectified immediately. The experience gained by print ing clouds in silver will enable any photographer to place the masks and shields correctly without difficulty when adding clouds to platinotype carbon, or bromide prints, though in these cesses there is no strong image to act as a guide.
The method of working in platinotype and carbon, inasmuch as they are daylight processes, will be similar to that described for silver print ing, but there is no image that can be seen sufficiently well through the cloud negative to assist in correctly placing the mask. In plat inotype, the image is an assistance, but it cannot be utilised in the same manner as in silver. When the landscape print is taken from the frame, a small pencil mark is made at each end of the print, at the exact point to which the mask has been cut ; and about an eighth of an inch above each mark, a second one is made to serve as a guide in placing the mask. These pencil marks are shown at E E. When the landscape is being arranged under the cloud negative, these pencil marks are of great assistance in securing the correct position. But their great value consists in the manner in which they enable the correct placing of the mask to be determined. They are plainly visible through the cloud negative, and the mask can be fitted to them as easily as to the strong image of a silver print. It is self-evident that if the mask is in the correct position at the two margins it must be in the correct position throughout its length. The exposure should be timed by means of an actinometer.
In carbon prints there is no image whatever to serve as a guide for marginal marks, and their position must be determined differently. A
little water-colour is required—white or light yellow—and a fine brush. When the print is in the frame, either before or after the exposure, one-half of the back of the frame is opened, and a fine mark is made on the margin of the negative at the spot corresponding with the mask. That half of the back of the frame is at once closed again so as to press the tissue on to the negative, and the moist colour will set off on to the margin of the print. While this half remains closed, the other half is opened and a similar mark made on the margin of the negative at the correct position for the mask. The precaution should be taken of opening each half separately a second time to ascertain that the colour has been transferred to the face of the tissue ; and, before removing the print, a mark should be made on the back to indicate which is the top. The exposed tissue should then be removed from the frame, the marks strengthened, and a second mark made just above each to correspond with the pencil marks in platinotype. With these marks the correct placing of the mask is easy, and this and the printing will be the same as described for platinotype. The appearance of the carbon print is shown at C, the white brush marks F F corresponding to E E in diagram A.
In bromide printing, the method of working is the same as in carbon, but a dark colour must be used for the brush marks, black or dark-brown. Diagram D illustrates a bromide print to be used with the mask B, the brush marks being indicated at G G. In bromide printing, the card shield must be kept moving during the exposure, to prevent a sharp line from appearing.
In enlarging by means of a lantern, pencil marks can be made on the enlargement, the image thrown by the lens forming the guide. The card shield may be held in any convenient position between the lens and the enlarging easel so as to shield the landscape, and it must be kept in motion throughout the exposure of the cloud negative.