Since I found out about herbariums and preserving plant material, I found this method of preserving nepenthes pitchers.
Basically all you need to do is cut the pitcher and throw the liquid from inside of the trap, then wash it with water to make sure there's nothing else inside and then wash it with a little bit of ethanol alcohol to remove the water. Grab a jar preferably glass(baby food jars...etc) and put the pitcher inside, then just put 70% ethanol alcohol until the whole pitcher is covered in the ethanol. I read somewhere online that it is recommended that you use 70% ethanol as there is something with 70% that does the trick(usually found at most stores). you MUST seal the container very well, triple tape or something to prevent evaporation or the ethanol from dripping out.
This pitcher of N. Sanguinea was placed there about two weeks ago. I also placed some orchids because they look very nice. Use this method of preserving plants that are very thick and heavy. I tried to put a rose in a jar, and it floats, so it really has to be something heavy.
The pros and cons: I find about this method as I read in a website is that the color of the plants tend to disappear due to the alcohol but as far as preserving the structure it is a great method. Also I don't like the idea of having jars with 70% ethanol as it is flammable so make sure to keep it out of the heat and place in shade or away from candles, lights..etc. You will need a lot of ethanol, so go to the dollar store and buy 10.