Photogram

A photogram is the shortest route from an object to an image. The object blocks light, the paper records where it was, and nothing else happens. There is no lens, no focus, no viewpoint and no distance, so the result is the true size and the true outline of the thing that lay there.

That is also the limit of the process, and it is worth stating plainly. A photogram shows an outline, not a picture. It cannot show the front of an object, or the side, or what colour it is. What it can show is the shape, the edge and how much light the material lets through, and a good photogram is chosen for those three things alone.

Lay the objects down. The paper goes on the bench, the objects go on the paper, and a lamp above exposes the lot. Where an object sits flat against the paper the edge is sharp. Where an object stands proud of the paper, light creeps under it and the edge goes soft and spreads. Say which of your objects touch and which do not.

Say what light does to each material. An opaque object gives a clean white shape. A translucent object gives grey, and a glass bottle gives bands of grey with bright lines where the glass focuses light. A mesh or a leaf gives a pattern of half tones. That range of greys is what stops a photogram from reading as a stencil.

Say there is no lens. Ask for no perspective, no horizon and no depth of field. The picture is flat and the whole sheet of paper is in it, edge to edge, so name the paper rectangle as part of the frame. Leave every camera word out of the prompt.

Use it for objects with a good outline: scissors, keys, lace, ferns, feathers, spectacles, wire, glassware. Anything read by its silhouette works, and anything read by its surface does not.

Leave it alone for a person, a place or a product. A face has no useful outline, a landscape has no outline at all, and a product needs its front shown, which a photogram cannot do.

Design publishes Cyanotype at /techniques/styles/, and the famous blue plant prints are photograms made in that process. A blue photogram belongs there, under print processes. This entry is the silver version: white on a deep black ground rather than white on Prussian blue.

Pinhole is still a camera. It has no lens, but it has a box, an aperture and a view of a scene, so it gives perspective and a horizon. A photogram has none of that.

Solarisation happens in the darkroom too, but it works on a normal photograph and reverses part of its tones. A photogram never had a photograph to start from.

The method is older than the camera photograph. The 1830s name was photogenic drawing, made by laying lace and leaves on salted paper in the sun. The 1840s cyanotype botanical books are the best known early set, and those sit in the design catalogue. The avant garde of the 1920s took the technique up for abstract work and gave it the names rayograph and schadograph, using keys, springs, combs and glass on the paper. It is still the first exercise in a darkroom class today, because it needs no camera, no enlarger and no negative.

The model returns a photograph of objects arranged on a black table. Say the objects lie directly on the light sensitive paper, and ask for white silhouettes with no visible surface detail at all.

The second failure is a shadow cast off to one side. The light comes from directly above, so the shape sits exactly where the object sat. Say no cast shadow, no perspective and no horizon.