Imagine that you've just been handed an innocuous-looking list from a botany professor. On this list (which is more of a scavenger-hunt, really) are items that are being requested for the coming semester's botany course. You scan the list and realize that: a) none of the items can be purchased, and b) you're going to have to be awfully creative in trying to find some of them. One of the items on the list is "a partially decayed leaf to show net venation." You are quick to realize that plants decay in moist environments, and that it is currently the middle of August in Sacramento, California where it won't rain until October.
Alright, don't panic. I'm sure there are plenty of Internet sites abounding on information on how-to-skeletonize-leaves. Once you wade through all of the information on "leaf skeletonizing insects" and "cabbage lacers", this should be a cinch. After all, if a caterpillar can do it...
Well, it turns out that skeletonizing leaves is neither simple nor well publicized. From what I have gathered, skeletonizing leaves started in China as a popular but secret art form. Things really took-off in Western culture thanks to Victorian-era English and their attentive fascination to gardening and death. What could be nicer than a photo album of your deceased relatives (with pictures taken POST-Morten) next to a lovely "shadow bouquet": the term offered for preserved leaves and flowers, especially those that show venation patterns and are bleached-white.
In present day, leaf skeletonizing has become a poplar way to make jewelry. Leaves are skeletonized, and then somehow plated with either gold or silver. And of course the process is a closely guarded secret.
Take all of this into account, and top it off by realizing that most internet sites offer information that has never been tested. But fear not intrepid botanists: of the top internet sites that I found, I am going to lead you what worked best for me! Through several days of research, I performed various experiments and discovered that, yes, it is possible to get beautiful venation patterns from leaves.
Warning: If you are trying any of this at home, please use utmost caution. If you are trying to involve your children in a fun craft, you should probably find something else to do together. The following processes involve caustic and/or flammable chemicals.
You will need:
a large pot to hold a basic pH solution
washing soda (sodium carbonate) OR
baking soda (sodium bicarbonate) (2 tsp./quart)
bleach (1:5 dilution)
70% isopropyl alcohol (rubbing alcohol)
a bowl of water
a spray bottle of water
a broad paint-brush (like you would paint a door-frame with)
a butter knife (or any other blunt, metal, hand-held object)
a small hand-broom (plastic or natural bristles) OR
a scrubbing brush
4x6 index cards
leaves (it seems that oak and ivy work the best, but you can always experiment)
Choose large, sturdy leaves that would be suitable for boiling. If your leaves are thin (such as birch, sycamore, alder) they will have the consistency of boiled spinach when you're done.
Choose leaves that aren't very waxy. Holly leaves can boil away for hours, and then come out of the pot unharmed!
Choose leaves that have a net-venation pattern (think fisherman's net, not parallel lines). Parallel venation is easy to isolate, but when your done boiling the leaves, all you have left are strings!
The best leaves I found for this were ivy and oak leaves, and one delicate leaf that is possibly cottonwood.
1.) You can either boil your leaves, pressure-cook your leaves, or both. When you boil your leaves be very careful: Baking soda is very basic, and washing soda is even more so. (Remember: base is the opposite of acid, and can be just as harmful!) Boil your leaves for about an hour making sure that they stay submerged. If you pressure-cook them, leave them for about twenty minutes.
2.) Remove a leaf from the solution with tongs, and then submerge it in a bowl of clean water to rinse.
3.) Transfer the leaf to a paper towel. Spray the leaf with water, and brush it with the paint brush so that it lays flat. Keep the leaf as wrinkle-free as possible.
4.) Using the blunt end of a butter knife, scrape away at the leaf along the veins. Different leaves require different pressures. You don't want the leaf to break, so be as gentle as you can. If membranes start to peel away, use tweezers to help them.
Keeping the leaf damp helps this process. For really delicate leaves that survived the boiling process, brushing with a paint brush is sometimes enough to remove the cell layers. Be diligent!
5.) Turn the leaf over gently, and scrape the other side. Dab at the leaf with the paint brush, bringing the bristles straight down each time (like stenciling). If your leaf is too delicate, and the veins begin to tear, do this:
a) put the leaf between to paper towels, remembering to keep the leaf moist
b) beat the paper towels with the sturdy brush. Come straight down each time as a side-to-side motion could tear the veins apart.
c) when you've really given the leaf a good pounding with the brush, gently remove the top paper towel. You should see pieces of the leaf that you don't want are sticking to this towel. Put the leaf between two fresh paper towels.
d) repeat as many times as necessary to get the desired results
It seems that this won't work for delicate leaves, but it does! The veins are composed of lignin... and this is the toughest material you'll find in the leaves.
6.) When you are satisfied that your leaf is a skeleton, soak the skeleton in a 1:5 solution of bleach for several hours, or even overnight (it depends on how white you want it), and then soak it in a bowl of fresh water. Bleaching will make the skeleton soft, however, so if you have a leaf that continuously folds on itself when you're trying to take it out of the water, do this:
a) keep the leaf in the bleach solution/fresh water
b) submerge a 4x6 index card and float the leaf skeleton over to it.
c) keep the top of the leaf flat against the card when you pull it out of the water; try to keep the leaf from wrinkling (this may take some time; be patient). You may have to make several attempts to remove the leaf from the water. Try bobbing the card up and down as you lift it to flatten out the wrinkled parts.
7.) Leave your leaf skeleton to dry on a solid surface. If you removed your leaf from the water using an index card, allow both the leaf and card to dry completely.
8.) Being gentle, and possibly using tweezers, lift the leaf skeleton away from the surface/paper. Use even pressure and go slowly. Even delicate leaves can be done this way.
If you've been looking for a method of skeletonizing leaves, you've probably found this useful.
Other Methods I Have Not Personally Tried:
1.) Should you want to do something stinky and time consuming, layer the leaves in between layers of newspaper and wet the whole thing. Leave in a water-tight container somewhere a fair distance from you, your loved ones, and all of your noses. Let rot until done (about 3 weeks).
2.) You could try to bury the leaves in wood-ashes. Ash is caustic (look what it did to the people of Pompeii), so in time you should be left with nice leaf skeletons. If not, then at least you tried something creative with the mess left-over in your fireplace. No fireplace? Use a charcoal grill to burn charcoal (or even wood).
Now that you are armed with your leaf skeletons, I leave you prepared for new and even more strange requests from your resident botany professor. Good luck!