Hi,
I got a file with suffix .pat (the extension is a Pattern Image file) and, for what I could know, this kinde of files are used with photoshop...
II haven't photshp, so I looked for knowing how to open this file, and the only suggestion that I found was to try (in Linux environment) with GIMP.
I hadn't success in this way, (using GIMP) so I would ask what other I can try ...