GPPS is fairly hard but quite glossy in a polished tool. HIPS is softer and will likely mark worse against any harder material. You may just need to vapor hone the tool to make the surface more matte which will hide the mar or scratch. A raised edge on the chip will also help lessen marking across the whole surface of the chip when it is slid across a flat surface, such as a table. GPPS will give you a metallic ring when dropped. HIPs will be more of a dull thud. Many people want their chips to have more weight. We added barrium sulfate to the chips to give them more heft.
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