The file extension MAC identifies bitmap images in MacPaint format. MacPaint is an early graphics application created for the original Apple Macintosh in 1984. The format is limited to the resolution 720x575 pixels (PAL image) and grayscale. The original MacPaint format also includes up to 38 patterns that are used in MacPaint for painting, but are usually ignored by other programs.
Most often resolving problems with opening MAC files is very simple. Just install an appropriate program that supports such files. All of the listed programs support MAC files, but may vary in offered function and purpose. Some programs may be capable only of viewing contents of MAC files or offer file conversion options, but may not be capable of editing such files.
It is possible that although a compatible program has been installed on user’s system, it is not used by the system to open it. This may happen because no default application was associated with this type of files. To associate MAC files with given application, select "Open with" from drop-down menu (accessed by right-clicking on the file). Then select from the list the program or application you want to be used to open this type of file. If the GraphicConverter applications is not on the list, select "Browse" option in order to manually locate the directory where GraphicConverter has been installed.
Sometimes problems with opening MAC files may not lie with the application itself, but can arise due to other causes, such as: