Cannot save as a package file

Everytime that I try to make a simple shirt or such in the studio, it saves to the folder as a paint file.  It will continue to let me go through the steps of making the item but it will on save as a PNG or DDS file & I cannot use it in my mods folder.  I have searched everywhere on here, youtube & the rest of the internet for a way to do this. There is a really simple video on YouTube make simple CC but my S4S folder does not come up like in the video.  Please help!