I've made earrings since the 90's, mostly selling them as a vendor at CCCC meetings, and then around 2000-2002, at craft shows in Michigan. I could make them effiiciently in some small quantities, and sold them pretty cheaply. Nowadays the business has evolved into mostly making large commercial cutters, and with all the requests for complex quotes for custom work, I just don't have time to make up earrings. Probably haven't made any since around 2002 or so, not even sure where the materials might be.
We used to sell them with the clips and backs as shown above. If requested, we sold them with the pressure clip for non-pierced ears, or with the "closed loop" type clip. See the following picture: