Stuffit for MAC's If your files are larger than 200k, it's always a good idea to compress your files before sending them to us, both for you and us. Compressing your MAC files with Stuffit has ZERO negative effects on the quality of the files you send us, and can only DRASTICALLY shorten the time it takes to upload your print-ready designs For MAC users, we recommend Stuffit. You can download a shareware version of the software for your version of Windows here. Stuffit is very easy and intuitive to use. Follow the installation instructions, and take the tutorial offered with the program. It's a small and quick program to learn, so you should not have problems putting it to work for you.