The Four Feather Types (image) University of Bristol Share Print E-Mail Caption These are the four feather types: filaments, filament bunches, tufted filament, down feather. Scale bars for photos, are a-d: 100μm, 200μm, 500μm and 1mm). Credit Zixiao Yang Usage Restrictions Single use only Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.