My own Plant Press Design
I use plant presses of my own design. I make them in three sizes, full size, half size and quarter size (and also pocket presses to make gathering specimens more convenient and safe for the small material collected when not on a serious specimen hunt with a plant press). I was never happy with plant presses with canvas straps. It didn't seem to me that pressure enough to do any good could ever be applied with the straps.
A very special lady friend who passed away several years ago at 96 gave me a small press made of press board and using bolts to close it. I liked the design but could readily see several innovations that would improve the design.
I use plywood which is sturdy and applies even pressure throughout the press. I use bolts only I introduced some changes. I anchor the bolts in the base with epoxy and slot the holes on the top, deeper on one side than the other. I use wing nuts and put a dollop of epoxy on the end of the bolts so the wing nuts will not come completely off so they can not be lost in the field. I stick felt pads on the bottom so the bolts don't mar any surface when the press is placed on a table or desk.
The top is removed by loosening the wing nuts, sliding the top so that it goes deeper into the longer slots until the shorter slots on the other side clear the bolts and nuts on the other side. Then raise the far side and slide the deep slots out from under the nuts on the near side.
Working without a budget on par with an institution I have to improvise with almost everything. I made a forced air dryer with a narrow box that is perfectly sized to hold a plant press. I mounted a slotted metal false bottom in the box to hold the press. I use a hair dryer to supply hot air through a hole below the metal shelf. I put the plant press in the dryer with the corrugations of the dryer separators running up and down so the warm air passes through them to heat each plant evenly. I leave the press in the hot air dryer for 8 hours or so and have beautifully dried and pressed specimens. All for very little cost.
Pocket Plant Press
I have been disappointed by curled, dried out specimens missing important parts from being carried by hand during a botanizing trip. Trying to carry specimens while collecting and studying specimens with a hand lens is difficult as well. Rembering information on each specimen is also difficult. So, I made a Pocket Plant Press to solve those problems for small specimens.
The Press is made of Plant Press dryer sheets cut down to 4" x 6" sheets and punched for binding. I carry a pencil inside the front sheet and scraps of paper in the back so notes can be made. That information sheet is transferred along with the specimen to a proper Plant Press once back at home.