I have been building a collection of laminated fern fronds.
I press fronds for a week between newspaper and cardboard, held by plywood, bolts, and springs,
and then run them through my laminating machine ($2/sheet @ STAPLES also works)
The result can be handled a bit roughly (passed around in class) without damage. The gross morphology is well preserved for ten years and counting. Fine detail may be damaged, and the color fades, slowly in the dark.
Several images I have posted are simply scans of those laminated sheets. (Others are digital photographs or scans of 35mm prints.)
I am reasonably pleased with the image quality of e.g. Polystichum braunii or Cystopteris tenuis.