ZIP / 7z etc. compression

uncompressed archive exclude folders

7zz a -mx0 -bb1 '-xr!.dropbox' '-xr!.dropbox.cache' "Snapshot.7z" /Volumes/Data/Dropbox

add to (uncompressed) archive with 7zip

a = add
-mx0 = no compression
-bb1 = do some logging
7zz a -mx0 -bb1 target.7z FOLDER

extract with 7zip

7z x filename.7z 

unzip to folder

unzip images.zip -d images