The present invention relates to a method of preparing a starch-based composition, characterized in that it comprises: mixing a starch substrate with sodium perborate; adding water to the mix of step to form a slurry; and pasting the slurry of step, provided that the method does not include, between steps and, the step of adding an effective amount of hydrolytic enzyme to the slurry. The fluted spinning tool of the present invention, when rotated at a predetermined speed into the free end of the tube, produces a combination of force, rotation, and heat which results in uniform expansion of the free end of the tube. In each heat treatment sub-zone there are also means for collecting the liquid which wet the products being treated. The tension-leveling apparatus is adapted to engage the sheet metal in a manner to subject the portion of the sheet metal between the first and second sets of bridle rollers to a tensile force. The test method may be used during manufacturing test or during function design verification. The high gain BJT is formed without added mask steps to the process flow.