Backup SL Disk

I bought the 3 license version of SL and would like to make a backup copy of the disk to keep at my office. Is that ok under the license agreement? If so, is it just a matter of using the disk utility to copy the disk?

Thanks!

It is legal to make a back up copy of your operating system to use on a day to day basis provided EULA laws are not infringed. Personally use Toast Titanium to copy DL data discs.