Paper used in laser printers has a specific finish that is very smooth and slick. Today, there are lots of finishes, including everything from matte to glossy. These papers cost more than the standard paper that can be used in an inkjet printer. Using the paper intended for the specific printer renders the best results. Using regular paper in a laser printer won't harm the printer, but the results will not be as crisp and clear as with paper intended for laser printers. Laser paper used in an inkjet printer won't harm the printer, but is a waste of more costly paper.