Fodder, according to the Merriam-Webster Dictionary, is coarse, dry food for livestock. So, in essence, journal fodder is food for your journal, and when you feed your journal, it gets fat. Journal fodder is all the ephemera that we as humans seem to collect and save. Fodder is all the mementos that people save - ticket stubs, photographs, labels, postcards, stickers, wrappers, maps, photocopies, etc. etc. etc. Most of the time people throw it all in boxes to keep for some time when they stumble across the box and paw through the memories. We, as Journal Fodder Junkies, glue those things into the visual journal and keep boxes, bins, piles, and stacks of fodder to use later.
We use mainly UHU Glue Stics to glue the collage material into the journals, and over time, the journals swell to 3 or 4 times their original thickness because of all the stuff glued in. The jumbo size lasts a while and is very portable.