This format was developed by Apple for storing vector and bitmap images with metadata. It was the main format for the QuickDraw graphics software. PCT supports 32-bit and 24-bit images. At the moment, the format is obsolete and has been superseded by more functional solutions.
This format is used for exchanging graphics data between SAPR programs. It was initially created for AutoCAD in 1982. It contains information regarding vector graphics in binary or ASCII. It’s used as an open alternative to the closed DWG format.