A lot of folks at pax were asking about how I made all the hard "feathers" for my "femris" cosplay (shoulder pauldrons, shinguards, gauntlets, etc), so I have put together a mini tutorial of how I make feathers. Alas the maintenance guy was unable to fix our fuses so it had to be done on my mac instead of my art pc, so it's not the prettiest tutorial ever.
Some additional notes: If you look at real bird feathers, you'll notice that they don't actually have those notches that everyone associates with feathers. This is because the individual shafts of the feathers themselves have barbs that hook onto each other, which also allow the bird to get airborne (among other things). Birds preen their feathers to prevent these hooks/barbs from coming apart. So these are much more stylized than real bird feathers (also somewhat cheaper- so save all your wonderflex scrap!) if you want to get all technical about it.
Generally I make a feather to step 4, then start another feather (rinse, repeat) and do all the notches at the same time. Beware of making too many notches as this will impact the structural integrity of your feather!
Also make sure that you connect like side with like (one side of wonderflex is smoother than the other, I use the smooth side as the outward side on my feathers). I also recommend attaching the feathers to whatever you're attaching them to (pauldron base, shinguard, gauntlet), before gessoing/painting.
For my pauldrons, I used black acrylic gesso (1-2 coats) first, then several coats of a mix of green, black, metallic silver (sparkly), and grey arcylic, followed up with a glossy acrylic varnish (depending on what you want, you can also get a matte or velvet varnish).
these feathers were pretty easy (if time consuming) to work with, so a good alternative for real feathers when you want it to look like a feather but not act like a feather (so good for a lot of DA2 armor where some concept artist went crazy with feathery armor)
