Files with pcz suffix can be most often found as pictures saved in the Compressed Macintosh PICT picture image format.
PCZ file extension - Compressed Macintosh PICT picture image file
What is pcz file? How to open pcz files?
File type specification:
File extension pcz is associated with the Compressed Macintosh PICT picture image file format used on original Macintosh computers for interchange both bitmap and vector graphics. It is integrated to QuickDraw Macintosh graphics library.