I have to drink a ton of water (yuck) so I always have a ton of bottle caps and after Michael suggested trying milk jug lids (the kind that are thicker and screw on) for another kind of joint it hit me that the little water bottle caps could make decent replacements for metal shank buttons and I get to recycle at the same time! It's also a ton cheaper when the budget will not allow for supply purchases LOL.
Above you can see the pictures. I popped a hole in a small clear bottle cap from a water bottle. I then placed a washer on a cotterpin (the washer gives added strength) and ran the cotterpin through the hole of the cap. Make sure the loop of the cotter pin and the washer are on the top of the lid. Then all you have to do is turn the cap over and curl the ends tight. Michael put it through a strength test and it held up great! Now I will say, a smaller cotterpin would really be better for the caps I have and will make a smaller amount to be covered by stuffing but even the size I had here at the house worked fine when tested and I could not see anything once inside etc.
I will be doing all these type of joints on Judi Ward's Bare Baby pattern. I have a head sewn and stuffed but have not been able to get any further. I will post pics once I am done to show how these joints worked out.