A lantern slide with a clear white sky is an unfinished production, and it is so simple a matter to put in clouds that there is no reason why such slides should be shown at all. The beginner must not think it is a difficult matter; and it is hoped that the following brief description will reveal its simplicity.
First make a slide in the usual way of a subject, which we will call the foreground or landscape slide. There may be more or less sky showing on it, but this must be quite clear. We take a sky negative, the lighting of the clouds being in accordance with the light in the foreground slide. Mark off from the sky negative with brown paper that portion of the sky negative on which the landscape would encroach, and proceed to make an exposure on a separate lantern plate for the sky only.
These two lantern plates when dry, and placed film to film, should fit together and form one whole slide. It is not at all a difficult matter, and a little practice will quickly turn even a beginner into quite an expert with the process.