Prepare the flammability samples by subjecting double sided laminate (unless you always use single sided laminate) to all steps of your manufacturing process. Remove all of the conductive material during etching. There should be no holes in the specimens and the edges should not be frayed. Note that the minimum thickness cannot be less than the minimum Recognized thickness of the base laminate. Also note in certain instances, UL assigns minimum thicknesses based on standard tolerances. For multilayer flame specimens, remove all conductive material from both the internal and the external surfaces of the samples during etching.