Like a lot of quilters, I sandwich my quilts with safety pins. I have many (over 4000) pins. I bought them from a dry cleaner supply store, where I was able to buy 10 gross (a gross is 144) of pins that were already open for about $8 plus shipping. I like my pins to be open because it is a pain to open them, stick them in the fabric, and the close them again.
After I quilted the six quilts, I put the pins I used back in the container I keep them in and they looked so cool, I had to take a photo of them.
Six quilts only used up about half of the pins shown.
This picture was really cool, I thought.
And here is my daughter holding up a bunch of pins by just one that linked a whole together (one disadvantage that leaving them open is that they tangle together).