There are two different ways you can create a password protected folder. The first way is by creating a new disk image using disk utility. The second is by creating a disk image from a folder that you already have.
In order to create a new disk image (password protected folder) you can follow the following steps:
- open disk utility
- click "file" then click "new image" then click "blank image"
- in the save as box set the name of the disk image (folder) you want to create
- choose the location where you want the disk image to be created (I recommend creating it on the desktop then moving it)
- set the name and size of the new disk image
- choose the format ( you can keep it at Mac OS Extended)
- choose the encryption type (128 is recommended unless you need something more secure) and input a password
- choose your partition type (I recommend GUID)
- chose the image type (if you want to be able to put files in and out of the disk image set this to "read/write disk image)
- click save
These steps will create a disk image with parameters you have set. Be aware that the size of the disk image (folder) is limited to initial creation size. The only way to change it is to create a new disk image. Also, make sure that you name it something that wont cause you to accidentally delete the disk image or get it confused with other disk images from other programs or installers.
[Edited by Moderator]