Compress files except of certain types

Hi all,

The folder I need to compress has the following structure
MyFolder
files
Subfolder
files

If I archive all the contents of MyFolder

do shell script "zip -r " & quoted form of toFile & " " & quoted form of MyFolder

all works fine
But when I try to do the same except of archiving *.psd files located in Subfolder

do shell script "zip -r " & quoted form of toFile & " " & quoted form of MyFolder" & " -x \\*.psd"

Archive stores absolute pathes instead relative
Where I’m wrong?