Fill in the Blanks What are Fibres?Online version Learn about what makes something a fibre and how they can be grouped. Refer to Pink Textbook p. 106. by Chelsea Ralph 1 animals 100 filament Protein Synthetic scientific natural Regenerated silk Staple Cellulose fibre 150mm A unit of matter may be classed as a if , when observed under a microscope , it is at least times longer that it is thick . Short fibres are also known as fibres . These are from 15 to long . Longer fibres , even up to 600m like some fibres , are known as fibres . Textile fibres can be classified according to their source - that is , according to where they come from . The two main categories are and manufactured . Natural fibres come from and plants . fibres are those that come from animals . fibres are those that come from plants . Manufactured fibres are made through processes and cannot be found in nature . fibres are made solely from chemical polymers . fibres are made from a mix of chemical and cellulose monomers .