Scale-mail probably won't work for this-- the manner in which the scales lay is the effect you want, but since the scales on regular scale-mail are all attached by rings, you wouldn't be able to do that with feathers.
Zentai and airbrushing sounds like it might be effective!
DeviantART // Tumblr // Facebook
- Fancy Mewtwo Gijinka (Cowslip Gijinka): 33% (Wig Styling) Otakon 2014
- Secret Cosplay (???): 100% (Ready!) Otakon 2014
- Magic Armor Link (LoZ: Twilight Princess): 15% (Patterning) Katsucon 2015
- Emperor Lelouch (Code Geass): 2% (Planning) Katsucon 2015