I did a google search and this is the closest thing I could find for you. Maybe you could adapt is somehow. Hope it helps
HOW TO MAKE WAFER PAPER TURKEY FEATHERS
Originated by Shirley Manbeck
Shirley said something about first making a mold of a feather shape out of Scuply (from craft store). (Then they won't be flat & will be better shapes). This is baked hard and is used over and over. I think she said she lays the feather in that mold and mists so she can get the shape better. This isn't needed so much if we use wafer paper pre-printed to color. Just so you know that this is another 'trick'. *You may be able to make molds using our Plastique also.
Cut out the feather shape.
Mist BACK lightly with 80 proof Vodka in a spray fine bottle or microwave 5 seconds (to soften the wafer paper). (Maybe you can use lemon extractI don't know.)
Fold in half length-wise, rough sides together. Make an indention for the quill, unfold before it dries.
Use a skewer for quill in centers of largest feathers. Wrap skewer with brown floral tape 2/3 of the way up the feather. Wrap again thicker and taper off thin towards the top as needed for thickness. Be sure, when wrapping, that you hold the tape in an angle so you don't get unsightly thickness.
Lay wafer paper on sculpy mold and mist top of feather. (I expect you can skip this part when pre-printed).
Pat feather down, rough side up. Attach skewer to back. I think water will hold it but I made no notes for that. Lay wax paper strip over feather and weight it down so it dries straight.
Dry on mold, remove. (This probably is not necessary when we have these pre-printed ones).
Put between wax paper & lay a book on it so it will dry flat.
Skewers - You could find these in cooking stores probably.
You will need some brown floral tape Split it lengthwise to use it so it won't get thick and built up too much unnaturally.
I have seen her feathers and they absolutely do look very real!