For backing up old files I tend to sort into lots of different folders, anything I am finished with I put in a 7zip Archive
The following batch makes use of a For loop in the batch, uses 7-zip with Ultra Compression and names the archive the same as the folder.

for /D %%X in (*) do "c:\Program Files\7-Zip\7z.exe" a -mx9 "%%X.7z" "%%X\"
pause

Credits: SS64