This drying PROCESS only refers to pressing and does not include information on the use of silica, the microwave, or the freeze-dry method.
Choosing a Press - Heavy books have been used for ages to press plants and they do work! The only difficulty is in maintaining an even pressing. A flower press is usually preferred for this reason. It consists of two solid pieces of wood and corner screws & wing-nuts to keep the pressure even. After a week, try tightening the screws to keep the pressure on as the plants dry. There are also portable wooden flower presses using Velcro straps (rather than screws and wing-nuts) to secure the plants in place. This is great if you are in the outdoors and want to take the press along with you. Whichever you decide to use, always try a sample plant before pressing that special flower or fern. Some plants are easier to press than others. It may take several tries and plenty of acid-free paper to get it right.
Pressing Fresh Flowers, Ferns, & Grasses - The best time to cut a flower or fern is in the late morning after the dew dries and before the hot sun causes wilting. Select a fresh flower and remove any petals or leaves that show signs of aging or bruising. Do the same for ferns, grasses, herbs, etc. No brown spots! They create holes when dried. Larger flowers may have to be separated from the stem before drying. Use sharp scissors and make the cut right where the stem meets the base of the flower. They can be reunited when dry!
Place the flower face-down on two sheets of acid-free paper (coffee filters also work well) and press gently. Press stem or leaves on the same sheet of paper as long as it does not touch the flower. Cover the flower with two more sheets of acid-free paper and put between sheets of cardboard before placing in a flower press. The cardboard gives the flower and stem some extra room to expand when pressed and it also aids in absorption. Be sure to apply equal pressure when using a flower press by tightening the wing nuts to the same level. If using Velcro strips, center the Velcro evenly to capture the entire surface.
If plants will be pressed in a book, then the use of cardboard is not necessary. However, extra sheets of paper may be needed to help with the absorption. Keep the flower press or book in a dry, cool place for about two weeks. Check on the drying process after the first week and change the paper if it appears to be damp or limp. At two weeks, the plants may be slightly attached to the paper. Lift the plant very gently if you must change the paper. If the plant will not lift, add a clean sheet of paper behind the damp papers. Flowers dry best if they are not disturbed at all.