PFM file extension is used by Microsoft Windows operating system for font files in Adobe Type 1 standard. PFM files isn’t a stand-alone document as its structure is strongly related with PFB format. The main purpose of PFM file is to ensure characters and glyphs are correctly scaled.

‘Type 1’ font standard was developed in 1985, originally for Apple computers. The standard uses two types of file instead of one used by more popular True Type standard, one being the PFM file. The standard uses Bézier curves to define shapes.