<P> The specific polymer used varies by manufacturer but can be a styrene acrylate copolymer, a polyester resin, a styrene butadiene copolymer, or a few other special polymers . Toner formulations vary from manufacturer to manufacturer and even from machine to machine . Typically formulation, granule size and melting point vary the most . </P> <P> Originally, the particle size of toner averaged 14--16 micrometres or greater . To improve image resolution, particle size was reduced, eventually reaching about 8--10 micrometers for 600 dots per inch resolution . Further reductions in particle size producing further improvements in resolution are being developed through the application of new technologies such as Emulsion - Aggregation . Toner manufacturers maintain a quality control standard for particle size distribution in order to produce a powder suitable for use in their printers . </P> <P> Toner has traditionally been made by compounding the ingredients and creating a slab which was broken or pelletized, then turned into a fine powder with a controlled particle size range by air jet milling . This process results in toner granules with varying sizes and aspherical shapes . To get a finer print, some companies are using a chemical process to grow toner particles from molecular reagents . This results in more uniform size and shapes of toner particles . The smaller, uniform shapes permit more accurate colour reproduction and more efficient toner use . </P> <P> Toner can be washed off skin and garments with cold water . Hot or warm water softens the toner, causing it to bond in place . Toner fused to skin eventually wears off, or can be partially removed using an abrasive hand cleaner . Toner fused to clothing usually cannot be removed . </P>

Which type of printer uses a powder like substance that