This part of EN 13900 specifies a method assessing the degree of dispersion of colorants ) and/or extenders in a thermoplastic polymer. The method is suitable for testing colorants and/or extenders in the form of concentrates or compounds in all polymers used for extrusion processes. NOTE – Defects, like gels, black specks, holes in the test film etc. are not in the scope of this standard. The film test result determined according to this method is valid only for the equipment, conditions and test polymer being used. The use of test conditions differing from those specified might give different results. The preparation methods of concentrates or compounds are not specified in this standard. The results obtained for individual colorants and/or extenders are therefore comparable only when the same conditions of preparation for concentrates or compounds and a comparable detection system are used.