PLT Import for SolidWorks is a HPGL Plot (.plt) file import add-in for SolidWorks?. This add-in gives SolidWorks the ability to import geometric data from PLT files. PLT Import for SolidWorks reads pen movement data stored PLT files and imports it into SolidWorks. A HPGL PLT file is comprised of a set of instructions related to pen movements of HPGL plotters. PLT Import for SolidWorks reads these pen movement instructions and creates curves.