These are caps of psilocybe semilanceata (collected in the Olympic Rain Forest) in a 1/2 pint wide mouth canning jar.
The caps are resting on 1/2 inch galvanized wire screen. The 1/2 inch is related to the distance between the wire. The wire screen was cut up and fashioned into a screen support by cutting it with a wire cutter pliars and bending it into shape. The caps are above the glass surface which makes for a cleaner spore print (although printing directly on glass apparantly works as well).
The glass jar and wire support are presterilized in a pressure canner. Jars like this can also use the white sterile filter disks as lids held on by the canning jar lid bands. These are available from Fungi Perfecti in Shelton Washington. To find them on the web - just do a search with FUNGI PERFECTI.
Seattle Washington USA