How do you make a "bean print"?

The procedure that follows is taken from Carol Reiss' text,

"Experiments in Plant Physiology" published by Prentice-Hall in 1993


MATERIALS REQUIRED
2 week old bean plants (dry kidney beans from the grocery store grow well)
NOTE:  Bean plants must be kept in the dark for 24-48 hours
before use to reduce the amount of starch in the leaves
rectangular glass bottles filled with water
large negative
plastic needlepoint mesh
100 watt light source
boiling water bath
hot 95% ethanol bath
rinse water bath
tongs, tape, foil, rubber bands etc.

I2KI reagent (dissolve 0.6g I2 in 5-10ml of 100% ethanol,
and dissolve 3g KI in 400mL water, then combine the solutions).


1)  Tape the negative to the bottle so that it bows outward.
 


2)  Place 3 rubber bands and the plastic mesh as shown.


3)  Insert the leaf between the mesh and negative, and slide the rubber bands up.
Try to align the leaf such that the main vein does not cut right through the face.
Remember, this is a contact print; the closer the contact between the leaf and
negative, the sharper the final image!


4)  Place the light and a second bottle as shown and expose the print for 1.5 hours.


5) Cut off the leaf and cut foil to fit.
6)  Using the foil as a spatula, carefully place the leaf in a boiling water bath for 30 seconds, then drain.
 


7)  Transfer the leaf through two hot ethanol baths.


8)  Make a foil tray.....

... then add I2KI reagent to "develop" the picture.

9)  Drain the iodine reagent, then transfer the leaf to a cold water bath.

10)  The image immediately after washing.
 


The final product, scanned on a flatbed scanner while still moist.

11)  To dry the bean print, place between copy paper, then paper towels, and press in a catalog.
The iodine will leach out of the print.  Once dry, re-develop with I2KI solution, wash in water,
and place on plastic coated side of Whatman "Benchkote".  Blot off excess water.  When
almost dry, put another sheet of Benchkote on top and press again.