There are a few things you should keep in mind when shopping for a plotter. First, consider the type of output you need. Plotters can produce monochrome or color output, and some can even produce three-dimensional prints. Next, think about the resolution you need. A plotter's resolution is measured in dots per inch (dpi), and generally speaking, the higher the dpi, the better the quality of the output. However, very high dpi plotters can be quite expensive, so it's important to strike a balance between quality and cost. Finally, take into account the size of the documents you'll be printing. Some plotters can only handle small format documents, while others are capable of printing on very large sheets of paper. Be sure to choose a plotter that can accommodate the size documents you'll be printing.