Insect collecting is a fragile art requiring patience, experience and gentle hands. To preserve and collect insects, you must first catch and kill the specimen, dry it and then mount it. Dried insects, especially dragonflies, are extremely fragile and must be handled with care, or else they will be ruined and thus killed needlessly. Dragonflies are especially good specimens because of their vibrant colors, but those colors are easily lost if not properly taken care of.
Remove the dragonfly from the net that you used to catch it. To remove the insect, hold the dragonfly by both wings and keep the abdomen straight. (Dragonflies will occasionally attempt to hold on the net with their jaws, and removal will pull their head off. They will also chew off their own abdomens once captured if their abdomen is not straight. So be careful. Place it in a paper or glassine envelope. Handle with care, and do not crush the envelope.
Create a killing jar to kill the dragonfly. Fill a wide-mouth jar one quarter full with absorbent material, and add ethyl acetate (hint: use nail polish remover) into the jar until it is absorbed.
Add the dragonfly. Make sure no liquid remains in the jar when you place the insect inside.
Leave the dragonfly inside the jar until it dies. It should be quick.
Arrange the insect how you want it to look permanently. Tweezers and insect pins are useful for arranging it and it is much easier to do before it has totally dried and become brittle.
Soak the dragonfly in acetone in a second wide-mouth jar for 8 to 12 hours or overnight. If you feel particularly confident, inject larger dragonflies with acetone before soaking. After you remove the insect from the jar, mount it with insect pins.
Dragonflies lose their colors very quickly, so minimize the time spent between removing the dragonfly from the killing jar and putting it in the acetone to soak. Acetone is only effective for a few insects, so use new acetone frequently. Before placing the insect inside the killing jar, you can place tissue paper strips inside the jar, allowing the insect a place to hide. This keeps it from hurting itself trying to escape.
The liquids and gases used to kill dragonflies are not good for humans to breathe, so avoid inhaling the fumes from the killing and preserving jars.