"Lumen Prints" are photograms that are created by overexposing classic photographic paper to sunlight (or a UV source). It is a very simple and experimental procedure that can be tried out even without a darkroom. The images are created by exposing the paper for several hours and are perfect for using some old photographic paper. After exposure, the resulting images can be easily scanned with a computer (since the photo paper is still light sensitive, it will continue to change and over time the image will no longer be visible), or you can use a fixer solution to fix the images.
List of materials
You need the following materials:
Contact frame or old picture frame (for example from ars imago)
Photographic paper (old paper)
For processing in the darkroom:
2 trays (for example from Paterson)
Fixing bath (for example ars-imago FX - Fixer Universal)
Print Tongs (for example Bamboo Print Tongs)
In the darkroom or in dim light, place various plants, leaves, flowers or other materials on the photo paper. (Attention! If you open the photo paper in dim light, it is no longer suitable for "normal" enlargements. The paper would already be exposed by light and would not work properly anymore! That's why we recommend old photo paper, which you would not use anymore).
Close contact frame so that the objects and photo paper can't move during exposure.
Expose the images to sunlight (or to an UV lamp). At least 60-90 minutes in sunlight, but feel free to experiment here. In general we recommend to expose the pictures as long as possible.
Processing without darkroom: Open the contact copy frame in dim light and remove the objects. Scan the photo paper as quickly as possible. Since the photo paper continues to react to light, the image will disappear over time, so scanning is the only way to capture the image.
Darkroom processing: Open the contact copy frame in dimmed light (or in the darkroom with red safelight) and remove the objects. First rinse photo paper in water for about 1-2 minutes. Then fix for 1-2 minutes and then water again. Approximately 5 minutes for RC paper and about 30 minutes for baryta paper. Change water several times. Then dry the pictures. The lumen prints are now safe to be exposed to light!
Note: Step 4 and 5 can be combined. Since the unfixed image looks different to the fixed image (the color changes during the fixing process), it is worth having both images! Scan the lumen prints as quick as possible and fix them afterwards.
Tips & tricks
Try different paper stocks. As each paper has a special emulsion, the results will always be different. Age and storage also have an influence on the image.
The lumen prints can also be toned. For example with a gold toner.
Basically, it is better to use longer times for the exposure, about 1-2h, better 4h.
Try to wet your paper or your objects! The paper will react differently.
In the slideshow you will find different results. We added the paper stocks as well.
Lumen Prints by Kilian Bannwart