The effort to preserve palm fronds makes for a drawn-out battle against nature, since plant materials generally decay and go back into the soil. But preserving anything is just a matter of knowing how to care for its individual material components. If you successfully create the proper environment, you will maximize the lifespan of the object you are trying to preserve. This also holds true for palm fronds.
Set up a workspace in a dry, out of the way location with a flat surface.
Tear off a sheet of wax paper and lay your palm frond flat on it. Place another sheet of wax paper on top.
Place heavy books on top of your palm frond, evenly distributing them so that no one part of the frond has more weight on it than another part.
Place silica gel packets around the pressed frond. Let the frond sit for two weeks. Check on it occasionally to see how the drying process is coming along.
Remove the books and peel back the wax paper. Take the frond to a well-ventilated area and place newspaper beneath it.
Don a face mask and spray the frond with acrylic spray. Flip it over after half an hour and spray the other side. Wait another half hour.
Spray the frond with a matte finish to remove the glossy appearance of the acrylic. Wait half an hour before flipping the frond over and spraying the other side.
For a long lasting piece, make sure the acrylic spray you have is non-yellowing.
Avoid storing the frond with plastics and metal.