Anthotypes
Anthotypes are a way to create fine art images right from a garden. This process was originally invented by Sir William Herschel in 1842. An emulsion is made from crushed flower petals or any other light-sensitive plant, fruit or vegetable. A coated sheet of paper is then dried, exposed to direct full sun-light until the image is bleached out. This is done ideally in a printing frame over 1-3 days or more depending on conditions and negative/material. What you see is what you get. No fixation is required. You can follow the gradually emerging image as you go. Results vary greatly from plant to plant and the strength of the emulsion employed. The resulting images are exquisite and often almost wispy or dream-like.
History
The photo-sensitive properties of plants and vegetables have been
known to scholars for centuries. Among many early observations the
experiments of Henri August Vogel in Paris are of particular interest.
He found in 1816:
When Herschel later that century attempted to invent a colour process, he tried several flower and plant emulsions and published his findings. His research resulted in what we now refer to as the anthotype process. It should be pointed out that his research into making photographic images from flowers was limited and was ultimately abandoned since no commercial application was feasible from a process which takes days to produce an image. The process continued to be listed in photographic the literature of the time but was likely little used.
How it works
I could not phrase it better than Snellingís description
which follows: "From an examination of the researches of Sir
John Herschel on the coloring matter of plants, it will be seen
that the action of the sun's rays is to destroy the colour, effecting
a sort of chromatic analysis, in which two distinct elements of
color are separated, by destroying the one and leaving the other
outstanding. The action is confined within the visible spectrum,
and thus a broad distinction is exhibited between the action of
the sun's rays on vegetable juices and on argentine compounds, the
latter being most sensibly affected by the invisible rays beyond
the violet. It may also be observed, that the rays effective in
destroying a given tint, are in a great many cases, those whose
union produces a color complementary to the tint destroyed, or,
at least, one belonging to that class of colors to which such complementary
tint may be preferred.
The method
1.Start with any flower you like although the following seem to
work well: poppies (images below were made with the red poppies
above) or peonies (Colin Heritage-Tilney). According to Henry
H. Snelling, the leaves of the laurel, common cabbage, and the
grasses, are found sufficiently sensitive. I have also tried
goldenseal and echinacea, but results were not encouraging.
The most important thing to remember is that many, many species
of flowers have never been explored. Crush the petals in a pestle
and mortar to a fine pulp and add a little distilled water as
you go. The purest water you can find is recommended since any
impurities will interfere with the delicate light sensitive
properties of the emulsion.
2.Using a clean simple brush coat any paper you like (hand-made paper being an extra nice touch) in nice even strokes vertically and horizontally leaving no pools of emulsion on the surface.
3.Dry the paper in the dark over-night or with a hand dryer on low heat.
4.Contact print any media or plant in a printing frame or clip frame. Expose in full sunlight over 1-3 days or more depending on your aesthetic. Done. The print can be kept in subdued or artificial light although exposure to direct sunlight is discouraged. A method of fixing anthotypes is not known and perhaps not necessary despite obvious limitations.