Cirrus clouds and aerosol fibers

 

  Cirrus clouds are the high altitude clouds.  They sometimes have a rather "fibrous" appearance due to the ice crystals which compose them.  Aerosol (chemtrail) clouds may resemble cirrus clouds because both are bright white and both may have a fibrous appearance.

 

   
But, natural clouds never look as fibrous as this
 
 
  or this:
.