ArlaJo, the basting gun uses tacks similar to the ones used at stores to hold the tags on clothing. They are kind of this shape: l---l
The tacks are made of plastic. To remove them, you just cut off one side, and the other side falls out. You just have to be careful not to use them on really lightweight fabrics, or they will definitely leave a mark or hole. Generally you can just press out the little marks they make, but it's always best to test first with the fabric you're using. Also, you can't quilt over them. I knew that this particular quilt was going to be straight-line quilted, so I just put them across in the areas I would not have to quilt over.
Maybe it will make more sense if you see what the whole thing looks like:
http://www.dritz.com/brands/showcase...?ITEM_NUM=3446
I tried to find a video but can't seem to locate one.