3.2. Calotypes and salted paper prints

While Louis Daguerre was the first to announce his technique, in the 1830s, the English scientist Henry Fox Talbot had also been working on a photographic process. The Calotype was a negative-positive method that permitted multiple prints of the same image. The negative was prepared by impregnating paper with light-sensitive chemicals, and then drying, exposing, and developing it to create a "paper negative." The print was usually made by contact printingthe negative and a sheet of similarly sensitized "salted paper" were sandwiched together under a piece of glass and exposed to bright sunlight. In France, the process was developed further with Gustave Le Gray's "waxed paper" process, which produced much finer detail, but Fox Talbot's patents and licensing fees limited its commercial appeal. Calotype negatives were rapidly superseded in the 1850s by the wet-plate collodion process.

Before coining the word "Calotype," Fox Talbot's early works involved placing leaves, lace, and other objects directly onto salted paper. No camera was involved in these "photogenic drawings." So, taking the idea of scanning real material one step further, you can do something similar using a flatbed scanner to capture objects such as the kiwi fruit in this recipe.

You will probably need to extract the objects from their background. Find some paper that has gentle fibers and scan that, toothis can be combined with the subject to imitate the paper negative's typical softness. A third quality, the sepia tone, is easy enough to create in Photoshop.

A thin slice of kiwi fruit and some bathroom tissue were scanned separately with an ordinary flatbed scanner. Be sure that you know how to clean the scanner glass properly so that any juice or liquid will not leave a mark.

If your subject is predominantly whitea piece of lace, for exampleplace it on the scanner with a plain, brightly colored card as a background. This will make it easier for you to isolate the item from the bcakground. Scan the item and then make a separate scan of the paper you've selected to use to add texture to the final image. Leave the windows of both scans open in Photoshop. Like the uneven gray-blue tone around my kiwi, your scan will probably capture some of the scanner's white lid or the colored sheet. To remove these areas, select the Eyedropper tool and click in one of those areas to sample the color. I sampled a pixel color that was somewhere between the darkest and the lightest gray-blue shade. Choose Select > Color Range. Sampling these pixels doesn't just set Photoshop's foreground color, it also makes the Color Range dialog box assume you want to select pixels matching the sampled color, and immediately selects those pixels. Check the Invert checkbox so that the fruit or other object is shown in white, meaning it will be selected, and adjust the Fuzziness slider until all the unwanted pixels show as black in the preview. Click OK. With the selection's marching ants active, check the Layers palette. If the image is shown as a locked background layer (with its name displayed in italics), double-click the thumbnail and rename the layer. This enables the layer to have transparent pixels. Click the "Add layer mask" icon. The unwanted pixels are hidden, or "masked." This technique is more flexible than simply deleting the pixels because it allows you to fine-tune the subject's edges, or redo the extraction entirely. Flexibility is also why I used Color Range rather than the Magic Wand, Filter > Extract, or the other selection tools. To combine the subject and the paper scan, drag the image layer from the Layers palette and drop it into the paper scan's window. Hold down the Shift key as you do so to automatically center the image. Change the image layer's blending mode to Multiply and the paper will show through (mimicking Calotype images, which were absorbed into the salted paper, unlike modern photographs where the image is usually a plastic coating). Add a Channel Mixer adjustment layer (see page 26) to make the picture monochrome. Early photographic processes had greater sensitivity to blue light, which made skies appear lighter and skin tones darker. To mimic this, use higher Blue channel values and lower Red channel values (don't treat this as gospel, thoughif other values look better for your particular image, go with them). To add the sepia tone typical of a Calotype, create a Hue/Saturation adjustment layer, tick the Colorize checkbox and set Hue to 30 and Saturation to 20. The Hue value may be lower or higherthe color of the Calotype varied between a reddish-brown and a yellowish tone. The colors were always subdued, so keep the saturation low. If you need to adjust the picture's contrast, add a Curves layer, but always aim for a low-contrast final result. Finally, salted paper prints did not have a glossy finish, so try to print your pseudo-Calotype onto matte paper. If the print has any borders, cut them right back with a guillotine or art knife so that the sepia tone extends to the paper's edge. For extra authenticity, you could cut little triangles off the corners, and then mount the print directly onto a card. Fox Talbot's earliest images were made without a camera by placing objects directly onto light-sensitive paper. You can use a flatbed scanner to capture both the subject and its textured surface.